diff --git a/backend/app/jobs/media_process_job.go b/backend/app/jobs/media_process_job.go
index 0a1eb23..33dfeff 100644
--- a/backend/app/jobs/media_process_job.go
+++ b/backend/app/jobs/media_process_job.go
@@ -114,7 +114,49 @@ func (j *MediaProcessWorker) Work(ctx context.Context, job *river.Job[args.Media
 				}
 			}
 		} else {
-			log.Warn("non-local provider, skipping ffmpeg processing")
+			tempDir, err := os.MkdirTemp("", "media-process-")
+			if err != nil {
+				log.Errorf("create temp dir failed: %v", err)
+				finalStatus = consts.MediaAssetStatusFailed
+			} else {
+				defer os.RemoveAll(tempDir)
+				ext := path.Ext(asset.ObjectKey)
+				inputFile := filepath.Join(tempDir, "source"+ext)
+				if err := j.storage.Download(ctx, asset.ObjectKey, inputFile); err != nil {
+					log.Errorf("download media file failed: %s, err=%v", asset.ObjectKey, err)
+					finalStatus = consts.MediaAssetStatusFailed
+				} else if _, err := exec.LookPath("ffmpeg"); err != nil {
+					log.Warn("ffmpeg not found, skipping real transcoding")
+				} else {
+					coverFile := filepath.Join(tempDir, "cover.jpg")
+					cmd := exec.CommandContext(
+						ctx,
+						"ffmpeg",
+						"-y",
+						"-i",
+						inputFile,
+						"-ss",
+						"00:00:00.000",
+						"-vframes",
+						"1",
+						"-vf",
+						"format=yuv420p",
+						"-update",
+						"1",
+						coverFile,
+					)
+					if out, err := cmd.CombinedOutput(); err != nil {
+						log.Errorf("ffmpeg failed: %s, output: %s", err, string(out))
+						finalStatus = consts.MediaAssetStatusFailed
+					} else {
+						log.Infof("Generated cover: %s", coverFile)
+						if err := j.registerCoverAsset(ctx, asset, coverFile); err != nil {
+							log.Errorf("register cover failed: %s", err)
+							finalStatus = consts.MediaAssetStatusFailed
+						}
+					}
+				}
+			}
 		}
 	}
 
@@ -175,21 +217,27 @@ func (j *MediaProcessWorker) registerCoverAsset(ctx context.Context, asset *mode
 	coverName := coverFilename(filename)
 	objectKey := buildObjectKey(tenant, hash, coverName)
 
-	// 本地存储将文件移动到目标 objectKey 位置，保持路径规范。
-	localPath := j.storage.Config.LocalPath
-	if localPath == "" {
-		localPath = "./storage"
-	}
-	dstPath := filepath.Join(localPath, filepath.FromSlash(objectKey))
-	if coverFile != dstPath {
-		if err := os.MkdirAll(filepath.Dir(dstPath), 0o755); err != nil {
-			return err
-		}
-		if _, err := os.Stat(dstPath); err == nil {
-			_ = os.Remove(coverFile)
-		} else if err := os.Rename(coverFile, dstPath); err != nil {
+	if strings.ToLower(asset.Provider) == "local" {
+		localPath := j.storage.Config.LocalPath
+		if localPath == "" {
+			localPath = "./storage"
+		}
+		dstPath := filepath.Join(localPath, filepath.FromSlash(objectKey))
+		if coverFile != dstPath {
+			if err := os.MkdirAll(filepath.Dir(dstPath), 0o755); err != nil {
+				return err
+			}
+			if _, err := os.Stat(dstPath); err == nil {
+				_ = os.Remove(coverFile)
+			} else if err := os.Rename(coverFile, dstPath); err != nil {
+				return err
+			}
+		}
+	} else {
+		if err := j.storage.PutObject(ctx, objectKey, coverFile, "image/jpeg"); err != nil {
 			return err
 		}
+		_ = os.Remove(coverFile)
 	}
 
 	coverAsset := &models.MediaAsset{
diff --git a/backend/app/jobs/media_process_job_test.go b/backend/app/jobs/media_process_job_test.go
new file mode 100644
index 0000000..fc5718b
--- /dev/null
+++ b/backend/app/jobs/media_process_job_test.go
@@ -0,0 +1,257 @@
+package jobs
+
+import (
+	"database/sql"
+	"io"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"testing"
+
+	"quyun/v2/app/commands/testx"
+	"quyun/v2/app/jobs/args"
+	"quyun/v2/database"
+	"quyun/v2/database/fields"
+	"quyun/v2/database/models"
+	"quyun/v2/pkg/consts"
+	"quyun/v2/providers/storage"
+
+	"github.com/riverqueue/river"
+	"github.com/rogeecn/fabfile"
+	. "github.com/smartystreets/goconvey/convey"
+	"github.com/stretchr/testify/suite"
+	"go.ipao.vip/atom/contracts"
+	"go.ipao.vip/gen/types"
+	"go.uber.org/dig"
+)
+
+type MediaProcessWorkerTestSuiteInjectParams struct {
+	dig.In
+
+	DB       *sql.DB
+	Initials []contracts.Initial `group:"initials"`
+	Storage  *storage.Storage
+}
+
+type MediaProcessWorkerLocalSuite struct {
+	suite.Suite
+	MediaProcessWorkerTestSuiteInjectParams
+}
+
+type MediaProcessWorkerS3Suite struct {
+	suite.Suite
+	MediaProcessWorkerTestSuiteInjectParams
+}
+
+func Test_MediaProcessWorkerLocal(t *testing.T) {
+	originEnv := os.Getenv("ENV_LOCAL")
+	if err := os.Setenv("ENV_LOCAL", "test"); err != nil {
+		t.Fatalf("set ENV_LOCAL failed: %v", err)
+	}
+	t.Cleanup(func() {
+		if originEnv == "" {
+			_ = os.Unsetenv("ENV_LOCAL")
+		} else {
+			_ = os.Setenv("ENV_LOCAL", originEnv)
+		}
+	})
+
+	providers := testx.Default()
+	testx.Serve(providers, t, func(p MediaProcessWorkerTestSuiteInjectParams) {
+		suite.Run(t, &MediaProcessWorkerLocalSuite{MediaProcessWorkerTestSuiteInjectParams: p})
+	})
+}
+
+func Test_MediaProcessWorkerS3(t *testing.T) {
+	originEnv := os.Getenv("ENV_LOCAL")
+	if err := os.Setenv("ENV_LOCAL", "minio"); err != nil {
+		t.Fatalf("set ENV_LOCAL failed: %v", err)
+	}
+	t.Cleanup(func() {
+		if originEnv == "" {
+			_ = os.Unsetenv("ENV_LOCAL")
+		} else {
+			_ = os.Setenv("ENV_LOCAL", originEnv)
+		}
+	})
+
+	providers := testx.Default()
+	testx.Serve(providers, t, func(p MediaProcessWorkerTestSuiteInjectParams) {
+		suite.Run(t, &MediaProcessWorkerS3Suite{MediaProcessWorkerTestSuiteInjectParams: p})
+	})
+}
+
+func (s *MediaProcessWorkerLocalSuite) Test_Work_Local() {
+	Convey("Work Local", s.T(), func() {
+		if _, err := exec.LookPath("ffmpeg"); err != nil {
+			s.T().Skip("ffmpeg not installed")
+		}
+
+		ctx := s.T().Context()
+		database.Truncate(ctx, s.DB, models.TableNameMediaAsset)
+
+		tempDir := s.T().TempDir()
+		fixturePath := fabfile.MustFind("fixtures/demo.mp4")
+		objectKey := path.Join("quyun", "public", "demo.mp4")
+		dstPath := filepath.Join(tempDir, filepath.FromSlash(objectKey))
+		So(copyFile(fixturePath, dstPath), ShouldBeNil)
+
+		info, err := os.Stat(dstPath)
+		So(err, ShouldBeNil)
+
+		So(s.Storage, ShouldNotBeNil)
+		s.Storage.Config.Type = "local"
+		s.Storage.Config.LocalPath = tempDir
+
+		asset := &models.MediaAsset{
+			TenantID:  1,
+			UserID:    1,
+			Type:      consts.MediaAssetTypeVideo,
+			Status:    consts.MediaAssetStatusUploaded,
+			Provider:  s.Storage.Provider(),
+			Bucket:    s.Storage.Bucket(),
+			ObjectKey: objectKey,
+			Meta: types.NewJSONType(fields.MediaAssetMeta{
+				Filename: "demo.mp4",
+				Size:     info.Size(),
+			}),
+		}
+		So(models.MediaAssetQuery.WithContext(ctx).Create(asset), ShouldBeNil)
+
+		worker := &MediaProcessWorker{storage: s.Storage}
+		err = worker.Work(ctx, &river.Job[args.MediaAssetProcessJob]{
+			Args: args.MediaAssetProcessJob{
+				TenantID: asset.TenantID,
+				AssetID:  asset.ID,
+			},
+		})
+		So(err, ShouldBeNil)
+
+		updated, err := models.MediaAssetQuery.WithContext(ctx).
+			Where(models.MediaAssetQuery.ID.Eq(asset.ID)).
+			First()
+		So(err, ShouldBeNil)
+		So(updated.Status, ShouldEqual, consts.MediaAssetStatusReady)
+
+		tbl, q := models.MediaAssetQuery.QueryContext(ctx)
+		cover, err := q.Where(
+			tbl.SourceAssetID.Eq(asset.ID),
+			tbl.Type.Eq(consts.MediaAssetTypeImage),
+		).First()
+		So(err, ShouldBeNil)
+		So(cover.ObjectKey, ShouldNotBeBlank)
+
+		coverPath := filepath.Join(tempDir, filepath.FromSlash(cover.ObjectKey))
+		_, err = os.Stat(coverPath)
+		So(err, ShouldBeNil)
+	})
+}
+
+func (s *MediaProcessWorkerS3Suite) Test_Work_S3() {
+	Convey("Work S3", s.T(), func() {
+		if _, err := exec.LookPath("ffmpeg"); err != nil {
+			s.T().Skip("ffmpeg not installed")
+		}
+
+		ctx := s.T().Context()
+		database.Truncate(ctx, s.DB, models.TableNameMediaAsset)
+
+		So(s.Storage, ShouldNotBeNil)
+		s.Storage.Config.Type = "s3"
+		s.Storage.Config.Endpoint = "http://127.0.0.1:9000"
+		s.Storage.Config.AccessKey = "minioadmin"
+		s.Storage.Config.SecretKey = "minioadmin"
+		s.Storage.Config.Region = "us-east-1"
+		s.Storage.Config.Bucket = "quyun-assets"
+		s.Storage.Config.PathStyle = true
+
+		fixturePath := fabfile.MustFind("fixtures/demo.mp4")
+		objectKey := path.Join("quyun", "public", "demo.mp4")
+		err := s.Storage.PutObject(ctx, objectKey, fixturePath, "video/mp4")
+		if err != nil {
+			s.T().Skipf("minio not available: %v", err)
+		}
+		s.T().Cleanup(func() {
+			_ = s.Storage.Delete(objectKey)
+		})
+
+		info, err := os.Stat(fixturePath)
+		So(err, ShouldBeNil)
+
+		asset := &models.MediaAsset{
+			TenantID:  1,
+			UserID:    1,
+			Type:      consts.MediaAssetTypeVideo,
+			Status:    consts.MediaAssetStatusUploaded,
+			Provider:  "s3",
+			Bucket:    s.Storage.Config.Bucket,
+			ObjectKey: objectKey,
+			Meta: types.NewJSONType(fields.MediaAssetMeta{
+				Filename: "demo.mp4",
+				Size:     info.Size(),
+			}),
+		}
+		So(models.MediaAssetQuery.WithContext(ctx).Create(asset), ShouldBeNil)
+
+		worker := &MediaProcessWorker{storage: s.Storage}
+		err = worker.Work(ctx, &river.Job[args.MediaAssetProcessJob]{
+			Args: args.MediaAssetProcessJob{
+				TenantID: asset.TenantID,
+				AssetID:  asset.ID,
+			},
+		})
+		So(err, ShouldBeNil)
+
+		updated, err := models.MediaAssetQuery.WithContext(ctx).
+			Where(models.MediaAssetQuery.ID.Eq(asset.ID)).
+			First()
+		So(err, ShouldBeNil)
+		So(updated.Status, ShouldEqual, consts.MediaAssetStatusReady)
+
+		tbl, q := models.MediaAssetQuery.QueryContext(ctx)
+		cover, err := q.Where(
+			tbl.SourceAssetID.Eq(asset.ID),
+			tbl.Type.Eq(consts.MediaAssetTypeImage),
+		).First()
+		So(err, ShouldBeNil)
+		So(cover.ObjectKey, ShouldNotBeBlank)
+		So(cover.Provider, ShouldEqual, "s3")
+
+		s.T().Cleanup(func() {
+			if cover.ObjectKey != "" {
+				_ = s.Storage.Delete(cover.ObjectKey)
+			}
+		})
+
+		downloadDir := s.T().TempDir()
+		downloadPath := filepath.Join(downloadDir, "cover.jpg")
+		So(s.Storage.Download(ctx, cover.ObjectKey, downloadPath), ShouldBeNil)
+
+		downloadInfo, err := os.Stat(downloadPath)
+		So(err, ShouldBeNil)
+		So(downloadInfo.Size(), ShouldBeGreaterThan, 0)
+	})
+}
+
+func copyFile(srcPath, dstPath string) error {
+	if err := os.MkdirAll(filepath.Dir(dstPath), 0o755); err != nil {
+		return err
+	}
+	src, err := os.Open(srcPath)
+	if err != nil {
+		return err
+	}
+	defer src.Close()
+
+	dst, err := os.Create(dstPath)
+	if err != nil {
+		return err
+	}
+	defer dst.Close()
+
+	if _, err := io.Copy(dst, src); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/backend/providers/storage/provider.go b/backend/providers/storage/provider.go
index 94b1a49..da12014 100644
--- a/backend/providers/storage/provider.go
+++ b/backend/providers/storage/provider.go
@@ -6,6 +6,7 @@ import (
 	"crypto/sha256"
 	"encoding/hex"
 	"fmt"
+	"io"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -63,6 +64,44 @@ type Storage struct {
 	s3Client *minio.Client
 }
 
+func (s *Storage) Download(ctx context.Context, key, filePath string) error {
+	if s.storageType() == "local" {
+		localPath := s.Config.LocalPath
+		if localPath == "" {
+			localPath = "./storage"
+		}
+		srcPath := filepath.Join(localPath, key)
+		if err := os.MkdirAll(filepath.Dir(filePath), 0o755); err != nil {
+			return err
+		}
+		src, err := os.Open(srcPath)
+		if err != nil {
+			return err
+		}
+		defer src.Close()
+
+		dst, err := os.Create(filePath)
+		if err != nil {
+			return err
+		}
+		defer dst.Close()
+
+		if _, err := io.Copy(dst, src); err != nil {
+			return err
+		}
+		return nil
+	}
+
+	client, err := s.s3ClientForUse()
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Dir(filePath), 0o755); err != nil {
+		return err
+	}
+	return client.FGetObject(ctx, s.Config.Bucket, key, filePath, minio.GetObjectOptions{})
+}
+
 func (s *Storage) Delete(key string) error {
 	if s.storageType() == "local" {
 		localPath := s.Config.LocalPath
diff --git a/docs/todo_list.md b/docs/todo_list.md
index 1c18aae..990197b 100644
--- a/docs/todo_list.md
+++ b/docs/todo_list.md
@@ -348,7 +348,7 @@
 - ✅ MinIO S3 Provider 配置可用（`config.prod.toml`）
 - ✅ 上传/访问/删除完整链路验证通过
 
-### 17) 媒体处理管线适配对象存储（S3/MinIO）
+### 17) 媒体处理管线适配对象存储（S3/MinIO）（已完成）
 **需求目标**
 - 在对象存储模式下，媒体处理任务可完整执行并回传产物。
 
@@ -356,10 +356,14 @@
 - Worker：从对象存储下载源文件到临时目录 → FFmpeg 处理 → 结果上传回对象存储 → 清理临时文件。
 - 产物：封面/预览片段自动生成并回写 `media_assets`。
 - 本地 FS 仍保留兼容路径（开发/测试使用）。
- - 进度：本地视频处理已可生成封面资产（ffmpeg 可用时）。
+- 已完成：
+  - `Storage.Download` 支持 local copy + S3 FGetObject
+  - `MediaProcessWorker` 支持对象存储流程（下载 → FFmpeg → 上传封面 → 清理）
+  - 封面派生资产在 S3 模式走 `PutObject`（不再 rename）
 
 **测试方案**
-- 对象存储模式下上传视频触发处理，封面/预览可访问；任务异常可重试。
+- ✅ `ENV_LOCAL=test go test ./backend/app/jobs -run Test_MediaProcessWorkerLocal -count=1`
+- ✅ `ENV_LOCAL=minio go test ./backend/app/jobs -run Test_MediaProcessWorkerS3 -count=1`
 
 ### 18) 支付集成
 **需求目标**
@@ -393,6 +397,7 @@
 - 性能优化（避免 N+1：订单/租户列表批量聚合 + topics 聚合）。
 - 多租户强隔离（/t/:tenantCode/v1 + TenantResolver）。
 - 真实存储 Provider 接入（生产 MinIO S3 配置与 E2E 验证）。
+- 媒体处理管线适配对象存储（S3/MinIO）。
 
 ## 里程碑建议
 - M1：完成 P0