diff --git a/store/tikv/coprocessor.go b/store/tikv/coprocessor.go
index 21482a2c0708f..f2d9cfe93287c 100644
--- a/store/tikv/coprocessor.go
+++ b/store/tikv/coprocessor.go
@@ -30,12 +30,15 @@ import (
 	"github.com/pingcap/failpoint"
 	"github.com/pingcap/kvproto/pkg/coprocessor"
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
+	"github.com/pingcap/tidb/distsql"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/metrics"
 	"github.com/pingcap/tidb/store/tikv/tikvrpc"
+	"github.com/pingcap/tidb/tablecodec"
 	"github.com/pingcap/tidb/util/execdetails"
 	"github.com/pingcap/tidb/util/logutil"
 	"github.com/pingcap/tidb/util/memory"
+	"github.com/pingcap/tidb/util/ranger"
 	"go.uber.org/zap"
 )
 
@@ -218,6 +221,13 @@ func buildCopTasks(bo *Backoffer, cache *RegionCache, ranges *copRanges, req *kv
 	if req.Streaming {
 		cmdType = tikvrpc.CmdCopStream
 	}
+	var tableStart, tableEnd kv.Key
+	if req.StoreType == kv.TiFlash {
+		tableID := tablecodec.DecodeTableID(ranges.at(0).StartKey)
+		fullRange := ranger.FullIntRange(false)
+		keyRange := distsql.TableRangesToKVRanges(tableID, fullRange, nil)
+		tableStart, tableEnd = keyRange[0].StartKey, keyRange[0].EndKey
+	}
 
 	var tasks []*copTask
 	appendTask := func(regionWithRangeInfo *KeyLocation, ranges *copRanges) {
@@ -239,7 +249,14 @@ func buildCopTasks(bo *Backoffer, cache *RegionCache, ranges *copRanges, req *kv
 				i = nextI
 			}
 		} else if req.StoreType == kv.TiFlash {
-			fullRange := kv.KeyRange{StartKey: regionWithRangeInfo.StartKey, EndKey: regionWithRangeInfo.EndKey}
+			left, right := regionWithRangeInfo.StartKey, regionWithRangeInfo.EndKey
+			if bytes.Compare(tableStart, left) >= 0 {
+				left = tableStart
+			}
+			if bytes.Compare(tableEnd, right) <= 0 || len(right) == 0 {
+				right = tableEnd
+			}
+			fullRange := kv.KeyRange{StartKey: left, EndKey: right}
 			tasks = append(tasks, &copTask{
 				region: regionWithRangeInfo.Region,
 				// TiFlash only support full range scan for the region, ignore the real ranges
diff --git a/store/tikv/coprocessor_test.go b/store/tikv/coprocessor_test.go
index 63e49393c736a..3e25f6e26e458 100644
--- a/store/tikv/coprocessor_test.go
+++ b/store/tikv/coprocessor_test.go
@@ -50,7 +50,7 @@ func (s *testCoprocessorSuite) TestBuildTasks(c *C) {
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("a", "c"), flashReq)
 	c.Assert(err, IsNil)
 	c.Assert(tasks, HasLen, 1)
-	s.taskEqual(c, tasks[0], regionIDs[0], "", "g")
+	s.taskEqual(c, tasks[0], regionIDs[0], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "g")
 
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("g", "n"), req)
 	c.Assert(err, IsNil)
@@ -60,7 +60,7 @@ func (s *testCoprocessorSuite) TestBuildTasks(c *C) {
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("g", "n"), flashReq)
 	c.Assert(err, IsNil)
 	c.Assert(tasks, HasLen, 1)
-	s.taskEqual(c, tasks[0], regionIDs[1], "g", "n")
+	s.taskEqual(c, tasks[0], regionIDs[1], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "n")
 
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("m", "n"), req)
 	c.Assert(err, IsNil)
@@ -70,7 +70,7 @@ func (s *testCoprocessorSuite) TestBuildTasks(c *C) {
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("m", "n"), flashReq)
 	c.Assert(err, IsNil)
 	c.Assert(tasks, HasLen, 1)
-	s.taskEqual(c, tasks[0], regionIDs[1], "g", "n")
+	s.taskEqual(c, tasks[0], regionIDs[1], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "n")
 
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("a", "k"), req)
 	c.Assert(err, IsNil)
@@ -81,8 +81,8 @@ func (s *testCoprocessorSuite) TestBuildTasks(c *C) {
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("a", "k"), flashReq)
 	c.Assert(err, IsNil)
 	c.Assert(tasks, HasLen, 2)
-	s.taskEqual(c, tasks[0], regionIDs[0], "", "g")
-	s.taskEqual(c, tasks[1], regionIDs[1], "g", "n")
+	s.taskEqual(c, tasks[0], regionIDs[0], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "g")
+	s.taskEqual(c, tasks[1], regionIDs[1], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "n")
 
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("a", "x"), req)
 	c.Assert(err, IsNil)
@@ -95,10 +95,10 @@ func (s *testCoprocessorSuite) TestBuildTasks(c *C) {
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("a", "x"), flashReq)
 	c.Assert(err, IsNil)
 	c.Assert(tasks, HasLen, 4)
-	s.taskEqual(c, tasks[0], regionIDs[0], "", "g")
-	s.taskEqual(c, tasks[1], regionIDs[1], "g", "n")
-	s.taskEqual(c, tasks[2], regionIDs[2], "n", "t")
-	s.taskEqual(c, tasks[3], regionIDs[3], "t", "")
+	s.taskEqual(c, tasks[0], regionIDs[0], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "g")
+	s.taskEqual(c, tasks[1], regionIDs[1], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "n")
+	s.taskEqual(c, tasks[2], regionIDs[2], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "t")
+	s.taskEqual(c, tasks[3], regionIDs[3], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "t\x80\x00\x00\x00\x00\x00\x00\x00_r\xff\xff\xff\xff\xff\xff\xff\xff\x00")
 
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("a", "b", "b", "c"), req)
 	c.Assert(err, IsNil)
@@ -108,7 +108,7 @@ func (s *testCoprocessorSuite) TestBuildTasks(c *C) {
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("a", "b", "b", "c"), flashReq)
 	c.Assert(err, IsNil)
 	c.Assert(tasks, HasLen, 1)
-	s.taskEqual(c, tasks[0], regionIDs[0], "", "g")
+	s.taskEqual(c, tasks[0], regionIDs[0], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "g")
 
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("a", "b", "e", "f"), req)
 	c.Assert(err, IsNil)
@@ -118,7 +118,7 @@ func (s *testCoprocessorSuite) TestBuildTasks(c *C) {
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("a", "b", "e", "f"), flashReq)
 	c.Assert(err, IsNil)
 	c.Assert(tasks, HasLen, 1)
-	s.taskEqual(c, tasks[0], regionIDs[0], "", "g")
+	s.taskEqual(c, tasks[0], regionIDs[0], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "g")
 
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("g", "n", "o", "p"), req)
 	c.Assert(err, IsNil)
@@ -129,8 +129,8 @@ func (s *testCoprocessorSuite) TestBuildTasks(c *C) {
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("g", "n", "o", "p"), flashReq)
 	c.Assert(err, IsNil)
 	c.Assert(tasks, HasLen, 2)
-	s.taskEqual(c, tasks[0], regionIDs[1], "g", "n")
-	s.taskEqual(c, tasks[1], regionIDs[2], "n", "t")
+	s.taskEqual(c, tasks[0], regionIDs[1], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "n")
+	s.taskEqual(c, tasks[1], regionIDs[2], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "t")
 
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("h", "k", "m", "p"), req)
 	c.Assert(err, IsNil)
@@ -141,8 +141,8 @@ func (s *testCoprocessorSuite) TestBuildTasks(c *C) {
 	tasks, err = buildCopTasks(bo, cache, buildCopRanges("h", "k", "m", "p"), flashReq)
 	c.Assert(err, IsNil)
 	c.Assert(tasks, HasLen, 2)
-	s.taskEqual(c, tasks[0], regionIDs[1], "g", "n")
-	s.taskEqual(c, tasks[1], regionIDs[2], "n", "t")
+	s.taskEqual(c, tasks[0], regionIDs[1], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "n")
+	s.taskEqual(c, tasks[1], regionIDs[2], "t\x80\x00\x00\x00\x00\x00\x00\x00_r\x00\x00\x00\x00\x00\x00\x00\x00", "t")
 }
 
 func (s *testCoprocessorSuite) TestSplitRegionRanges(c *C) {