diff --git a/pkg/dbutil/retry.go b/pkg/dbutil/retry.go
index 5949c2c9b..4c2784750 100644
--- a/pkg/dbutil/retry.go
+++ b/pkg/dbutil/retry.go
@@ -26,6 +26,8 @@ var (
 	Retryable1105Msgs = []string{
 		"Information schema is out of date",
 		"Information schema is changed",
+		"context deadline exceeded",
+		"exceeding the deadline",
 	}
 )
 
diff --git a/sync_diff_inspector/source/mysql_shard.go b/sync_diff_inspector/source/mysql_shard.go
index 004b8195e..23d5d3e59 100644
--- a/sync_diff_inspector/source/mysql_shard.go
+++ b/sync_diff_inspector/source/mysql_shard.go
@@ -316,7 +316,7 @@ func NewMySQLSources(ctx context.Context, tableDiffs []*common.TableDiff, ds []*
 				if sourceDB.Router != nil {
 					targetSchema, targetTable, err = sourceDB.Router.Route(schema, table)
 					if err != nil {
-						return nil, errors.Errorf("get route result for %d source %s.%s failed, error %v", i, schema, table, err)
+						return nil, errors.Errorf("get route result for %d source %s.%s failed, please check the rules of schema/table routes, error %v", i, schema, table, err)
 					}
 				}
 				uniqueId := utils.UniqueID(targetSchema, targetTable)
diff --git a/sync_diff_inspector/source/tidb.go b/sync_diff_inspector/source/tidb.go
index 842cb6d6a..209a1ae61 100644
--- a/sync_diff_inspector/source/tidb.go
+++ b/sync_diff_inspector/source/tidb.go
@@ -228,7 +228,7 @@ func getSourceTableMap(ctx context.Context, tableDiffs []*common.TableDiff, ds *
 			if ds.Router != nil {
 				targetSchema, targetTable, err = ds.Router.Route(schema, table)
 				if err != nil {
-					return nil, errors.Errorf("get route result for %s.%s failed, error %v", schema, table, err)
+					return nil, errors.Errorf("get route result for %s.%s failed, please check the rules of schema/table routes, error %v", schema, table, err)
 				}
 			}
 
diff --git a/sync_diff_inspector/utils/utils.go b/sync_diff_inspector/utils/utils.go
index 78cfccfd4..c9aaa3548 100644
--- a/sync_diff_inspector/utils/utils.go
+++ b/sync_diff_inspector/utils/utils.go
@@ -22,6 +22,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/olekukonko/tablewriter"
 	"github.com/pingcap/errors"
@@ -741,10 +742,23 @@ func GetCountAndCRC32Checksum(ctx context.Context, db *sql.DB, schemaName, table
 
 	var count sql.NullInt64
 	var checksum sql.NullInt64
-	err := db.QueryRowContext(ctx, query, args...).Scan(&count, &checksum)
-	if err != nil {
-		log.Warn("execute checksum query fail", zap.String("query", query), zap.Reflect("args", args), zap.Error(err))
-		return -1, -1, errors.Trace(err)
+	var err error
+	for i := 0; i < dbutil.DefaultRetryTime; i++ {
+		err = db.QueryRowContext(ctx, query, args...).Scan(&count, &checksum)
+		if err != nil {
+			if dbutil.IsRetryableError(err) && i < dbutil.DefaultRetryTime-1 {
+				select {
+				case <-ctx.Done():
+					return -1, -1, errors.Trace(ctx.Err())
+				case <-time.After(10 * time.Millisecond):
+				}
+				log.Warn("execute checksum query timeout, retry...", zap.Int("retry count", i+1))
+				continue
+			}
+			log.Warn("execute checksum query fail", zap.String("query", query), zap.Reflect("args", args), zap.Error(err))
+			return -1, -1, errors.Trace(err)
+		}
+		break
 	}
 	if !count.Valid || !checksum.Valid {
 		// if don't have any data, the checksum will be `NULL`