diff --git a/dm/pkg/checker/table_structure.go b/dm/pkg/checker/table_structure.go
index bf758d1c40d..4d199327722 100644
--- a/dm/pkg/checker/table_structure.go
+++ b/dm/pkg/checker/table_structure.go
@@ -95,6 +95,7 @@ func NewTablesChecker(dbs map[string]*sql.DB, tableMap map[string][]*filter.Tabl
 		tableMap:    tableMap,
 		dumpThreads: dumpThreads,
 	}
+	log.L().Logger.Debug("check table structure", zap.Int("channel pool size", dumpThreads))
 	c.inCh = make(chan *checkItem, dumpThreads)
 	c.optCh = make(chan *incompatibilityOption, dumpThreads)
 	return c
@@ -120,10 +121,12 @@ func (c *TablesChecker) Check(ctx context.Context) *Result {
 			return c.checkTable(checkCtx)
 		})
 	}
-
-	dispatchTableItem(checkCtx, c.tableMap, c.inCh)
+	// start consuming results before dispatching
+	// or the dispatching thread could be blocked when
+	// the output channel is full.
 	c.wg.Add(1)
 	go c.handleOpts(ctx, r)
+	dispatchTableItem(checkCtx, c.tableMap, c.inCh)
 	if err := eg.Wait(); err != nil {
 		c.reMu.Lock()
 		markCheckError(r, err)
@@ -188,6 +191,7 @@ func (c *TablesChecker) checkTable(ctx context.Context) error {
 				return nil
 			}
 			table := checkItem.table
+			log.L().Logger.Debug("checking table", zap.String("db", table.Schema), zap.String("table", table.Name))
 			if len(sourceID) == 0 || sourceID != checkItem.sourceID {
 				sourceID = checkItem.sourceID
 				p, err = dbutil.GetParserForDB(ctx, c.dbs[sourceID])
@@ -214,6 +218,7 @@ func (c *TablesChecker) checkTable(ctx context.Context) error {
 				opt.tableID = table.String()
 				c.optCh <- opt
 			}
+			log.L().Logger.Debug("finish checking table", zap.String("db", table.Schema), zap.String("table", table.Name))
 		}
 	}
 }
@@ -456,7 +461,9 @@ func (c *ShardingTablesChecker) checkShardingTable(ctx context.Context, r *Resul
 				r.Extra = fmt.Sprintf("error on sharding %s", c.targetTableID)
 				r.Instruction = "please set same table structure for sharding tables"
 				c.reMu.Unlock()
-				return nil
+				// shouldn't return error
+				// it's feasible to check more sharding tables and
+				// able to inform users of as many as possible incompatible tables
 			}
 		}
 	}
diff --git a/dm/pkg/checker/table_structure_test.go b/dm/pkg/checker/table_structure_test.go
index 8626b6c340b..efa6348501a 100644
--- a/dm/pkg/checker/table_structure_test.go
+++ b/dm/pkg/checker/table_structure_test.go
@@ -94,6 +94,45 @@ func (t *testCheckSuite) TestShardingTablesChecker(c *tc.C) {
 	c.Assert(result.State, tc.Equals, StateFailure)
 	c.Assert(result.Errors, tc.HasLen, 1)
 	c.Assert(mock.ExpectationsWereMet(), tc.IsNil)
+
+	// 4. test tiflow#5759
+	checker = NewShardingTablesChecker("test-name",
+		map[string]*sql.DB{"test-source": db},
+		map[string][]*filter.Table{"test-source": {
+			{Schema: "test-db", Name: "test-table-1"},
+			{Schema: "test-db", Name: "test-table-2"},
+			{Schema: "test-db", Name: "test-table-3"},
+			{Schema: "test-db", Name: "test-table-4"},
+		}},
+		false,
+		1)
+	mock = initShardingMock(mock)
+	createTableRow2 = sqlmock.NewRows([]string{"Table", "Create Table"}).
+		AddRow("test-table-2", `CREATE TABLE "test-table-2" (
+  "c" varchar(20) NOT NULL,
+  PRIMARY KEY ("c")
+) ENGINE=InnoDB DEFAULT CHARSET=latin1`)
+	mock.ExpectQuery("SHOW CREATE TABLE `test-db`.`test-table-2`").WillReturnRows(createTableRow2)
+	createTableRow3 := sqlmock.NewRows([]string{"Table", "Create Table"}).
+		AddRow("test-table-3", `CREATE TABLE "test-table-3" (
+  "c" varchar(20) NOT NULL,
+  "c2" INT,
+  PRIMARY KEY ("c")
+) ENGINE=InnoDB DEFAULT CHARSET=latin1`)
+	mock.ExpectQuery("SHOW CREATE TABLE `test-db`.`test-table-3`").WillReturnRows(createTableRow3)
+	createTableRow4 := sqlmock.NewRows([]string{"Table", "Create Table"}).
+		AddRow("test-table-4", `CREATE TABLE "test-table-4" (
+  "c" varchar(20) NOT NULL,
+  "c2" INT,
+  "c3" INT,
+  PRIMARY KEY ("c")
+) ENGINE=InnoDB DEFAULT CHARSET=latin1`)
+	mock.ExpectQuery("SHOW CREATE TABLE `test-db`.`test-table-4`").WillReturnRows(createTableRow4)
+
+	// in tiflow#5759, this function will enter deadlock
+	result = checker.Check(ctx)
+	c.Assert(result.State, tc.Equals, StateFailure)
+	c.Assert(result.Errors, tc.HasLen, 3)
 }
 
 func (t *testCheckSuite) TestTablesChecker(c *tc.C) {
@@ -174,6 +213,41 @@ func (t *testCheckSuite) TestTablesChecker(c *tc.C) {
 	c.Assert(result.State, tc.Equals, StateFailure)
 	c.Assert(result.Errors, tc.HasLen, 1)
 	c.Assert(mock.ExpectationsWereMet(), tc.IsNil)
+
+	// test #5759
+	maxConnectionsRow = sqlmock.NewRows([]string{"Variable_name", "Value"}).
+		AddRow("max_connections", "2")
+	mock.ExpectQuery("SHOW VARIABLES LIKE 'max_connections'").WillReturnRows(maxConnectionsRow)
+	sqlModeRow = sqlmock.NewRows([]string{"Variable_name", "Value"}).
+		AddRow("sql_mode", "ANSI_QUOTES")
+	mock.ExpectQuery("SHOW VARIABLES LIKE 'sql_mode'").WillReturnRows(sqlModeRow)
+	createTableRow1 := sqlmock.NewRows([]string{"Table", "Create Table"}).
+		AddRow("test-table-1", `CREATE TABLE "test-table-1" (
+  "c" int(11) NOT NULL
+) ENGINE=InnoDB`)
+	createTableRow2 := sqlmock.NewRows([]string{"Table", "Create Table"}).
+		AddRow("test-table-2", `CREATE TABLE "test-table-2" (
+  "c" int(11) NOT NULL
+) ENGINE=InnoDB`)
+	createTableRow3 := sqlmock.NewRows([]string{"Table", "Create Table"}).
+		AddRow("test-table-3", `CREATE TABLE "test-table-3" (
+  "c" int(11) NOT NULL
+) ENGINE=InnoDB`)
+	mock.ExpectQuery("SHOW CREATE TABLE `test-db`.`test-table-1`").WillReturnRows(createTableRow1)
+	mock.ExpectQuery("SHOW CREATE TABLE `test-db`.`test-table-2`").WillReturnRows(createTableRow2)
+	mock.ExpectQuery("SHOW CREATE TABLE `test-db`.`test-table-3`").WillReturnRows(createTableRow3)
+
+	checker = NewTablesChecker(
+		map[string]*sql.DB{"test-source": db},
+		map[string][]*filter.Table{"test-source": {
+			{Schema: "test-db", Name: "test-table-1"},
+			{Schema: "test-db", Name: "test-table-2"},
+			{Schema: "test-db", Name: "test-table-3"},
+		}},
+		1)
+	result = checker.Check(ctx)
+	c.Assert(result.State, tc.Equals, StateFailure)
+	c.Assert(result.Errors, tc.HasLen, 3)
 }
 
 func (t *testCheckSuite) TestOptimisticShardingTablesChecker(c *tc.C) {
diff --git a/dm/tests/check_task/conf/dm-master.toml b/dm/tests/check_task/conf/dm-master.toml
new file mode 100644
index 00000000000..2145761ed40
--- /dev/null
+++ b/dm/tests/check_task/conf/dm-master.toml
@@ -0,0 +1,4 @@
+# Master Configuration.
+advertise-addr = "127.0.0.1:8261"
+auto-compaction-retention = "3s"
+master-addr = ":8261"
diff --git a/dm/tests/check_task/conf/dm-worker1.toml b/dm/tests/check_task/conf/dm-worker1.toml
new file mode 100644
index 00000000000..3e71a5bdb55
--- /dev/null
+++ b/dm/tests/check_task/conf/dm-worker1.toml
@@ -0,0 +1,2 @@
+join = "127.0.0.1:8261"
+name = "worker1"
diff --git a/dm/tests/check_task/conf/source1.yaml b/dm/tests/check_task/conf/source1.yaml
new file mode 100644
index 00000000000..fae9f5bd7ee
--- /dev/null
+++ b/dm/tests/check_task/conf/source1.yaml
@@ -0,0 +1,11 @@
+source-id: mysql-replica-01
+flavor: ''
+enable-gtid: true
+enable-relay: true
+relay-binlog-name: ''
+relay-binlog-gtid: ''
+from:
+  host: 127.0.0.1
+  user: root
+  password: /Q7B9DizNLLTTfiZHv9WoEAKamfpIUs=
+  port: 3306
diff --git a/dm/tests/check_task/conf/task-noshard.yaml b/dm/tests/check_task/conf/task-noshard.yaml
new file mode 100644
index 00000000000..e22c8ec54f4
--- /dev/null
+++ b/dm/tests/check_task/conf/task-noshard.yaml
@@ -0,0 +1,32 @@
+---
+name: test
+task-mode: "all"
+is-sharding: false
+meta-schema: "dm_meta"
+# enable-heartbeat: true
+heartbeat-update-interval: 1
+heartbeat-report-interval: 1
+clean-dump-file: false
+
+target-database:
+  host: "127.0.0.1"
+  port: 4000
+  user: "test"
+  password: "/Q7B9DizNLLTTfiZHv9WoEAKamfpIUs="
+
+mysql-instances:
+  - source-id: "mysql-replica-01"
+    block-allow-list:  "instance"
+    mydumper-config-name: "global"
+
+
+block-allow-list:
+  instance:
+    do-dbs: ["checktask"]
+
+mydumpers:
+  global:
+    threads: 1
+    chunk-filesize: 64
+    skip-tz-utc: true
+    extra-args: ""
\ No newline at end of file
diff --git a/dm/tests/check_task/conf/task-sharding.yaml b/dm/tests/check_task/conf/task-sharding.yaml
new file mode 100644
index 00000000000..06c547057a2
--- /dev/null
+++ b/dm/tests/check_task/conf/task-sharding.yaml
@@ -0,0 +1,32 @@
+name: test             # 任务名称，需要全局唯一
+task-mode: all         # 任务模式，可设为 "full"、"incremental"、"all"
+shard-mode: "pessimistic"
+
+target-database:       # 下游数据库实例配置
+  host: "127.0.0.1"
+  port: 4000
+  user: "root"
+  password: ""         # 如果密码不为空，则推荐使用经过 dmctl 加密的密文
+
+## ******** 功能配置集 **********
+block-allow-list:        # 上游数据库实例匹配的表的 block-allow-list 过滤规则集，如果 DM 版本 <= v2.0.0-beta.2 则使用 black-white-list
+  bw-rule-1:             # 黑白名单配置的名称
+    do-dbs: ["checktask"] # 迁移哪些库
+
+# ----------- 实例配置 -----------
+mysql-instances:
+  - source-id: "mysql-replica-01"  # 上游实例或者复制组 ID，参考  的  配置
+    block-allow-list:  "bw-rule-1" # 黑白名单配置名称，如果 DM 版本 <= v2.0.0-beta.2 则使用 black-white-list
+    route-rules: ["rule1"]
+    mydumper-config-name: "global"
+
+routes:
+  rule1:
+    schema-pattern: "checktask"
+    table-pattern: "t*"
+    target-schema: "checktask"
+    target-table: "t"
+
+mydumpers:
+  global:
+    threads: 1
\ No newline at end of file
diff --git a/dm/tests/check_task/data/db1.prepare.sql b/dm/tests/check_task/data/db1.prepare.sql
new file mode 100644
index 00000000000..530f652b54a
--- /dev/null
+++ b/dm/tests/check_task/data/db1.prepare.sql
@@ -0,0 +1,12 @@
+use checktask;
+create table t1(c int primary key);
+
+create table t2(c int primary key, c2 int);
+
+create table t3(c int primary key, c3 int);
+
+create table t4(c int primary key, c4 int);
+
+create table t5(c int primary key, c5 int);
+
+create table t6(c int primary key, c6 int);
\ No newline at end of file
diff --git a/dm/tests/check_task/run.sh b/dm/tests/check_task/run.sh
new file mode 100644
index 00000000000..3d8716852f2
--- /dev/null
+++ b/dm/tests/check_task/run.sh
@@ -0,0 +1,55 @@
+#!/bin/bash
+set -eu
+cur=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+source $cur/../_utils/test_prepare
+WORK_DIR=$TEST_DIR/$TEST_NAME
+
+TABLE_NUM=20
+
+function prepare_incompatible_tables() {
+	run_sql_both_source "drop database if exists checktask"
+	run_sql_both_source "create database if not exists checktask"
+	for i in $(seq $TABLE_NUM); do
+		run_sql_both_source "create table checktask.test${i}(id int, b varchar(10))" # no primary key
+	done
+}
+
+function prepare_many_tables() {
+	run_sql_both_source "drop database if exists checktask"
+	run_sql_both_source "create database if not exists checktask"
+	run_sql_file $cur/data/db1.prepare.sql $MYSQL_HOST1 $MYSQL_PORT1 $MYSQL_PASSWORD1
+}
+
+function prepare() {
+	run_dm_master $WORK_DIR/master $MASTER_PORT $cur/conf/dm-master.toml
+	check_rpc_alive $cur/../bin/check_master_online 127.0.0.1:$MASTER_PORT
+	run_dm_worker $WORK_DIR/worker1 $WORKER1_PORT $cur/conf/dm-worker1.toml
+	check_rpc_alive $cur/../bin/check_worker_online 127.0.0.1:$WORKER1_PORT
+	dmctl_operate_source create $cur/conf/source1.yaml $SOURCE_ID1
+}
+
+function test_check_task_fail_no_block() {
+	prepare_incompatible_tables
+	run_dm_ctl $WORK_DIR "127.0.0.1:$MASTER_PORT" \
+		"check-task $cur/conf/task-noshard.yaml" \
+		"\"state\": \"fail\"" 1
+}
+
+function test_check_task_fail_no_block_forsharding() {
+	prepare_many_tables
+	run_dm_ctl $WORK_DIR "127.0.0.1:$MASTER_PORT" \
+		"check-task $cur/conf/task-sharding.yaml" \
+		"\"state\": \"fail\"" 1
+}
+
+function run() {
+	prepare
+	test_check_task_fail_no_block
+	test_check_task_fail_no_block_forsharding
+}
+
+cleanup_data checktask
+cleanup_process $*
+run $*
+cleanup_process $*
+cleanup_data checktask
diff --git a/dm/tests/others_integration_1.txt b/dm/tests/others_integration_1.txt
index 1832c30f48e..3a0adc9033e 100644
--- a/dm/tests/others_integration_1.txt
+++ b/dm/tests/others_integration_1.txt
@@ -1,3 +1,4 @@
+check_task
 validator_basic
 drop_column_with_index
 downstream_diff_index