diff --git a/backend/db/migration/registry.go b/backend/db/migration/registry.go
index f6857c01..0c6379be 100644
--- a/backend/db/migration/registry.go
+++ b/backend/db/migration/registry.go
@@ -1,5 +1,10 @@
 package migration
 
+import (
+	"regexp"
+	"strings"
+)
+
 func DefaultMigrations() []Migration {
 	return []Migration{
 		WithCompatibleChecksums(
@@ -22,3 +27,27 @@ func DefaultMigrations() []Migration {
 		DefineCustom(15, "expand_security_setup", "expand_security_setup_v1", applySecuritySetupSchema),
 	}
 }
+
+var sqliteIndexDefinitionPattern = regexp.MustCompile(`(?i)^CREATE\s+(?:UNIQUE\s+)?INDEX\s+(?:IF\s+NOT\s+EXISTS\s+)?["` + "`" + `]([^"` + "`" + `]+)["` + "`" + `]`)
+
+// ManagedSQLiteIndexNames 返回版本化迁移允许存在的 SQLite 索引名称。
+// 自动生成的 sqlite_autoindex_* 不包含在列表中，由 SQLite 自身维护。
+func ManagedSQLiteIndexNames() map[string]struct{} {
+	managed := make(map[string]struct{})
+	for _, item := range DefaultMigrations() {
+		for _, statement := range item.StatementsFor(DialectSQLite) {
+			matches := sqliteIndexDefinitionPattern.FindStringSubmatch(strings.TrimSpace(statement))
+			if len(matches) == 2 {
+				managed[matches[1]] = struct{}{}
+			}
+		}
+	}
+	for _, name := range []string{
+		"uq_user_email_address_canonical",
+		"idx_user_email_user_primary",
+		"idx_verification_event_expires_at",
+	} {
+		managed[name] = struct{}{}
+	}
+	return managed
+}
diff --git a/backend/services/dbmigration/portable_schema.go b/backend/services/dbmigration/portable_schema.go
index 93a0fed6..2160c42a 100644
--- a/backend/services/dbmigration/portable_schema.go
+++ b/backend/services/dbmigration/portable_schema.go
@@ -2,16 +2,16 @@ package dbmigration
 
 import (
 	"context"
+	"database/sql"
+	"strings"
 
 	"git.pcux.cn/xuans/Smail/config"
+	"git.pcux.cn/xuans/Smail/db/migration"
 )
 
 // 仅迁移 Smail 版本化业务表；不能静默忽略自定义对象。
 func validatePortableObjects(ctx context.Context, database portableQuery, kind config.DatabaseType) error {
 	queries := []string{"SELECT COUNT(*) FROM sqlite_master WHERE type IN ('view','trigger')"}
-	if kind == config.DatabaseTypeSQLite {
-		queries = append(queries, "SELECT COUNT(*) FROM sqlite_master WHERE type='index' AND sql IS NOT NULL")
-	}
 	switch kind {
 	case config.DatabaseTypeMySQL:
 		queries = []string{
@@ -42,5 +42,33 @@ func validatePortableObjects(ctx context.Context, database portableQuery, kind c
 			return ErrSQLUnsupportedObject
 		}
 	}
+	if kind == config.DatabaseTypeSQLite {
+		if err := validateSQLiteIndexes(ctx, database); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func validateSQLiteIndexes(ctx context.Context, database portableQuery) error {
+	rows, err := database.QueryContext(ctx, "SELECT name, sql FROM sqlite_master WHERE type='index' AND sql IS NOT NULL")
+	if err != nil {
+		return ErrSQLUnsupportedObject
+	}
+	defer rows.Close()
+	managed := migration.ManagedSQLiteIndexNames()
+	for rows.Next() {
+		var name string
+		var definition sql.NullString
+		if err := rows.Scan(&name, &definition); err != nil || !definition.Valid || strings.TrimSpace(definition.String) == "" {
+			return ErrSQLUnsupportedObject
+		}
+		if _, ok := managed[name]; !ok {
+			return ErrSQLUnsupportedObject
+		}
+	}
+	if err := rows.Err(); err != nil {
+		return ErrSQLUnsupportedObject
+	}
 	return nil
 }