diff --git a/server/internal/service/replication_service_test.go b/server/internal/service/replication_service_test.go
new file mode 100644
index 0000000..a5c657d
--- /dev/null
+++ b/server/internal/service/replication_service_test.go
@@ -0,0 +1,154 @@
+package service
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"backupx/server/internal/backup"
+	"backupx/server/internal/config"
+	"backupx/server/internal/database"
+	"backupx/server/internal/logger"
+	"backupx/server/internal/model"
+	"backupx/server/internal/repository"
+	"backupx/server/internal/storage"
+	"backupx/server/internal/storage/codec"
+	storageRclone "backupx/server/internal/storage/rclone"
+)
+
+type replicationTestHarness struct {
+	repl      *ReplicationService
+	execution *BackupExecutionService
+	records   repository.BackupRecordRepository
+	destDir   string
+	srcDir    string
+}
+
+func newReplicationTestHarness(t *testing.T) *replicationTestHarness {
+	t.Helper()
+	baseDir := t.TempDir()
+	sourceData := filepath.Join(baseDir, "data")
+	srcStore := filepath.Join(baseDir, "src-store")
+	destStore := filepath.Join(baseDir, "dest-store")
+	if err := os.MkdirAll(sourceData, 0o755); err != nil {
+		t.Fatalf("mkdir data: %v", err)
+	}
+	if err := os.WriteFile(filepath.Join(sourceData, "index.html"), []byte("hello-replicate"), 0o644); err != nil {
+		t.Fatalf("write data: %v", err)
+	}
+	log, err := logger.New(config.LogConfig{Level: "error"})
+	if err != nil {
+		t.Fatalf("logger.New: %v", err)
+	}
+	db, err := database.Open(config.DatabaseConfig{Path: filepath.Join(baseDir, "backupx.db")}, log)
+	if err != nil {
+		t.Fatalf("database.Open: %v", err)
+	}
+	cipher := codec.NewConfigCipher("replicate-secret")
+	targets := repository.NewStorageTargetRepository(db)
+	tasks := repository.NewBackupTaskRepository(db)
+	records := repository.NewBackupRecordRepository(db)
+	replications := repository.NewReplicationRecordRepository(db)
+	nodes := repository.NewNodeRepository(db)
+
+	mkTarget := func(name, basePath string) {
+		cfg, err := cipher.EncryptJSON(map[string]any{"basePath": basePath})
+		if err != nil {
+			t.Fatalf("EncryptJSON: %v", err)
+		}
+		if err := targets.Create(context.Background(), &model.StorageTarget{Name: name, Type: string(storage.ProviderTypeLocalDisk), Enabled: true, ConfigCiphertext: cfg, ConfigVersion: 1, LastTestStatus: "unknown"}); err != nil {
+			t.Fatalf("create target %s: %v", name, err)
+		}
+	}
+	mkTarget("src", srcStore)   // ID 1
+	mkTarget("dest", destStore) // ID 2
+
+	task := &model.BackupTask{Name: "repl-test", Type: "file", Enabled: true, SourcePath: sourceData, StorageTargetID: 1, NodeID: 0, RetentionDays: 30, Compression: "gzip", MaxBackups: 10, LastStatus: "idle"}
+	if err := tasks.Create(context.Background(), task); err != nil {
+		t.Fatalf("create task: %v", err)
+	}
+
+	logHub := backup.NewLogHub()
+	runnerRegistry := backup.NewRegistry(backup.NewFileRunner(), backup.NewSQLiteRunner(), backup.NewMySQLRunner(nil), backup.NewPostgreSQLRunner(nil))
+	storageRegistry := storage.NewRegistry(storageRclone.NewLocalDiskFactory())
+	execution := NewBackupExecutionService(tasks, records, targets, storageRegistry, runnerRegistry, logHub, nil, cipher, nil, baseDir, 2, 10, "")
+	repl := NewReplicationService(replications, records, targets, nodes, storageRegistry, cipher, baseDir, 2)
+
+	return &replicationTestHarness{repl: repl, execution: execution, records: records, destDir: destStore, srcDir: srcStore}
+}
+
+func countFiles(t *testing.T, dir string) int {
+	t.Helper()
+	n := 0
+	_ = filepath.Walk(dir, func(_ string, info os.FileInfo, err error) error {
+		if err == nil && info != nil && !info.IsDir() {
+			n++
+		}
+		return nil
+	})
+	return n
+}
+
+// TestReplicationService_MirrorsToDestTarget 覆盖正常路径：把成功备份从源存储复制到目标存储，
+// 目标出现对象、源保留（复制非移动），记录终态为 success。
+func TestReplicationService_MirrorsToDestTarget(t *testing.T) {
+	h := newReplicationTestHarness(t)
+	ctx := context.Background()
+	backupDetail, err := h.execution.RunTaskByIDSync(ctx, 1)
+	if err != nil {
+		t.Fatalf("RunTaskByIDSync: %v", err)
+	}
+	if backupDetail.Status != "success" {
+		t.Fatalf("expected backup success, got %s", backupDetail.Status)
+	}
+	if countFiles(t, h.destDir) != 0 {
+		t.Fatalf("dest store should be empty before replication")
+	}
+
+	done := make(chan struct{})
+	h.repl.async = func(job func()) {
+		go func() { job(); close(done) }()
+	}
+	summary, err := h.repl.Start(ctx, backupDetail.ID, 2, "tester")
+	if err != nil {
+		t.Fatalf("replication Start: %v", err)
+	}
+	select {
+	case <-done:
+	case <-time.After(15 * time.Second):
+		t.Fatal("replication did not complete in time")
+	}
+
+	final, err := h.repl.Get(ctx, summary.ID)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if final.Status != model.ReplicationStatusSuccess {
+		t.Fatalf("expected replication success, got %s (err=%s)", final.Status, final.ErrorMessage)
+	}
+	if countFiles(t, h.destDir) == 0 {
+		t.Fatal("dest store should contain the replicated object")
+	}
+	if countFiles(t, h.srcDir) == 0 {
+		t.Fatal("source object must remain after replication (copy, not move)")
+	}
+}
+
+// TestReplicationService_RejectsSameTarget 校验：目标与源相同时同步拒绝。
+func TestReplicationService_RejectsSameTarget(t *testing.T) {
+	h := newReplicationTestHarness(t)
+	ctx := context.Background()
+	backupDetail, err := h.execution.RunTaskByIDSync(ctx, 1)
+	if err != nil {
+		t.Fatalf("RunTaskByIDSync: %v", err)
+	}
+	// 备份写到 target 1；以 target 1 作为复制目标应被拒绝。
+	if _, err := h.repl.Start(ctx, backupDetail.ID, 1, "tester"); err == nil {
+		t.Fatal("expected error when dest target equals source")
+	} else if !strings.Contains(err.Error(), "目标存储无效或与源相同") {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}