diff --git a/dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/controller/SchedulerController.java b/dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/controller/SchedulerController.java
index 0e1ca4d3ab..03e8db63c3 100644
--- a/dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/controller/SchedulerController.java
+++ b/dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/controller/SchedulerController.java
@@ -160,7 +160,7 @@ public class SchedulerController extends BaseController {
                                  @RequestParam(value = "failureStrategy", required = false, defaultValue = "END") FailureStrategy failureStrategy,
                                  @RequestParam(value = "workerGroup", required = false, defaultValue = "default") String workerGroup,
                                  @RequestParam(value = "environmentCode", required = false, defaultValue = "-1") Long environmentCode,
-                                 @RequestParam(value = "processInstancePriority", required = false) Priority processInstancePriority) {
+                                 @RequestParam(value = "processInstancePriority", required = false, defaultValue = DEFAULT_PROCESS_INSTANCE_PRIORITY) Priority processInstancePriority) {
 
         Map<String, Object> result = schedulerService.updateSchedule(loginUser, projectCode, id, schedule,
             warningType, warningGroupId, failureStrategy, processInstancePriority, workerGroup, environmentCode);
diff --git a/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_h2.sql b/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_h2.sql
index 0467b291b3..acff9b3bfd 100644
--- a/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_h2.sql
+++ b/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_h2.sql
@@ -331,7 +331,7 @@ CREATE TABLE t_ds_command
     start_time                 datetime DEFAULT NULL,
     executor_id                int(11) DEFAULT NULL,
     update_time                datetime DEFAULT NULL,
-    process_instance_priority  int(11) DEFAULT NULL,
+    process_instance_priority  int(11) DEFAULT '2',
     worker_group               varchar(64),
     environment_code           bigint(20) DEFAULT '-1',
     dry_run                    int NULL DEFAULT 0,
@@ -385,7 +385,7 @@ CREATE TABLE t_ds_error_command
     schedule_time              datetime DEFAULT NULL,
     start_time                 datetime DEFAULT NULL,
     update_time                datetime DEFAULT NULL,
-    process_instance_priority  int(11) DEFAULT NULL,
+    process_instance_priority  int(11) DEFAULT '2',
     worker_group               varchar(64),
     environment_code           bigint(20) DEFAULT '-1',
     message                    text,
@@ -475,7 +475,7 @@ CREATE TABLE t_ds_task_definition
     task_type               varchar(50) NOT NULL,
     task_params             longtext,
     flag                    tinyint(2) DEFAULT NULL,
-    task_priority           tinyint(4) DEFAULT NULL,
+    task_priority           tinyint(4) DEFAULT '2',
     worker_group            varchar(200) DEFAULT NULL,
     environment_code        bigint(20) DEFAULT '-1',
     fail_retry_times        int(11) DEFAULT NULL,
@@ -508,7 +508,7 @@ CREATE TABLE t_ds_task_definition_log
     task_type               varchar(50) NOT NULL,
     task_params             text,
     flag                    tinyint(2) DEFAULT NULL,
-    task_priority           tinyint(4) DEFAULT NULL,
+    task_priority           tinyint(4) DEFAULT '2',
     worker_group            varchar(200) DEFAULT NULL,
     environment_code        bigint(20) DEFAULT '-1',
     fail_retry_times        int(11) DEFAULT NULL,
@@ -604,7 +604,7 @@ CREATE TABLE t_ds_process_instance
     is_sub_process             int(11) DEFAULT '0',
     executor_id                int(11) NOT NULL,
     history_cmd                text,
-    process_instance_priority  int(11) DEFAULT NULL,
+    process_instance_priority  int(11) DEFAULT '2',
     worker_group               varchar(64)  DEFAULT NULL,
     environment_code           bigint(20) DEFAULT '-1',
     timeout                    int(11) DEFAULT '0',
@@ -797,7 +797,7 @@ CREATE TABLE t_ds_schedules
     release_state             tinyint(4) NOT NULL,
     warning_type              tinyint(4) NOT NULL,
     warning_group_id          int(11) DEFAULT NULL,
-    process_instance_priority int(11) DEFAULT NULL,
+    process_instance_priority int(11) DEFAULT '2',
     worker_group              varchar(64) DEFAULT '',
     environment_code          bigint(20) DEFAULT '-1',
     create_time               datetime     NOT NULL,
diff --git a/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_mysql.sql b/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_mysql.sql
index 14dbaa5221..0a155748f5 100644
--- a/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_mysql.sql
+++ b/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_mysql.sql
@@ -339,7 +339,7 @@ CREATE TABLE `t_ds_command` (
   `start_time`                datetime DEFAULT NULL COMMENT 'start time',
   `executor_id`               int(11) DEFAULT NULL COMMENT 'executor id',
   `update_time`               datetime DEFAULT NULL COMMENT 'update time',
-  `process_instance_priority` int(11) DEFAULT NULL COMMENT 'process instance priority: 0 Highest,1 High,2 Medium,3 Low,4 Lowest',
+  `process_instance_priority` int(11) DEFAULT '2' COMMENT 'process instance priority: 0 Highest,1 High,2 Medium,3 Low,4 Lowest',
   `worker_group`              varchar(64)  COMMENT 'worker group',
   `environment_code`          bigint(20) DEFAULT '-1' COMMENT 'environment code',
   `dry_run`                   tinyint(4) DEFAULT '0' COMMENT 'dry run flag：0 normal, 1 dry run',
@@ -391,7 +391,7 @@ CREATE TABLE `t_ds_error_command` (
   `schedule_time` datetime DEFAULT NULL COMMENT 'scheduler time',
   `start_time` datetime DEFAULT NULL COMMENT 'start time',
   `update_time` datetime DEFAULT NULL COMMENT 'update time',
-  `process_instance_priority` int(11) DEFAULT NULL COMMENT 'process instance priority, 0 Highest,1 High,2 Medium,3 Low,4 Lowest',
+  `process_instance_priority` int(11) DEFAULT '2' COMMENT 'process instance priority, 0 Highest,1 High,2 Medium,3 Low,4 Lowest',
   `worker_group` varchar(64)  COMMENT 'worker group',
   `environment_code` bigint(20) DEFAULT '-1' COMMENT 'environment code',
   `message` text COMMENT 'message',
@@ -475,7 +475,7 @@ CREATE TABLE `t_ds_task_definition` (
   `task_type` varchar(50) NOT NULL COMMENT 'task type',
   `task_params` longtext COMMENT 'job custom parameters',
   `flag` tinyint(2) DEFAULT NULL COMMENT '0 not available, 1 available',
-  `task_priority` tinyint(4) DEFAULT NULL COMMENT 'job priority',
+  `task_priority` tinyint(4) DEFAULT '2' COMMENT 'job priority',
   `worker_group` varchar(200) DEFAULT NULL COMMENT 'worker grouping',
   `environment_code` bigint(20) DEFAULT '-1' COMMENT 'environment code',
   `fail_retry_times` int(11) DEFAULT NULL COMMENT 'number of failed retries',
@@ -507,7 +507,7 @@ CREATE TABLE `t_ds_task_definition_log` (
   `task_type` varchar(50) NOT NULL COMMENT 'task type',
   `task_params` longtext COMMENT 'job custom parameters',
   `flag` tinyint(2) DEFAULT NULL COMMENT '0 not available, 1 available',
-  `task_priority` tinyint(4) DEFAULT NULL COMMENT 'job priority',
+  `task_priority` tinyint(4) DEFAULT '2' COMMENT 'job priority',
   `worker_group` varchar(200) DEFAULT NULL COMMENT 'worker grouping',
   `environment_code` bigint(20) DEFAULT '-1' COMMENT 'environment code',
   `fail_retry_times` int(11) DEFAULT NULL COMMENT 'number of failed retries',
@@ -606,7 +606,7 @@ CREATE TABLE `t_ds_process_instance` (
   `is_sub_process` int(11) DEFAULT '0' COMMENT 'flag, whether the process is sub process',
   `executor_id` int(11) NOT NULL COMMENT 'executor id',
   `history_cmd` text COMMENT 'history commands of process instance operation',
-  `process_instance_priority` int(11) DEFAULT NULL COMMENT 'process instance priority. 0 Highest,1 High,2 Medium,3 Low,4 Lowest',
+  `process_instance_priority` int(11) DEFAULT '2' COMMENT 'process instance priority. 0 Highest,1 High,2 Medium,3 Low,4 Lowest',
   `worker_group` varchar(64) DEFAULT NULL COMMENT 'worker group id',
   `environment_code` bigint(20) DEFAULT '-1' COMMENT 'environment code',
   `timeout` int(11) DEFAULT '0' COMMENT 'time out',
@@ -792,7 +792,7 @@ CREATE TABLE `t_ds_schedules` (
   `release_state` tinyint(4) NOT NULL COMMENT 'release state. 0:offline,1:online ',
   `warning_type` tinyint(4) NOT NULL COMMENT 'Alarm type: 0 is not sent, 1 process is sent successfully, 2 process is sent failed, 3 process is sent successfully and all failures are sent',
   `warning_group_id` int(11) DEFAULT NULL COMMENT 'alert group id',
-  `process_instance_priority` int(11) DEFAULT NULL COMMENT 'process instance priority：0 Highest,1 High,2 Medium,3 Low,4 Lowest',
+  `process_instance_priority` int(11) DEFAULT '2' COMMENT 'process instance priority：0 Highest,1 High,2 Medium,3 Low,4 Lowest',
   `worker_group` varchar(64) DEFAULT '' COMMENT 'worker group id',
   `environment_code` bigint(20) DEFAULT '-1' COMMENT 'environment code',
   `create_time` datetime NOT NULL COMMENT 'create time',
diff --git a/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_postgresql.sql b/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_postgresql.sql
index db83a0faf4..4cbbff20b6 100644
--- a/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_postgresql.sql
+++ b/dolphinscheduler-dao/src/main/resources/sql/dolphinscheduler_postgresql.sql
@@ -262,7 +262,7 @@ CREATE TABLE t_ds_command (
   start_time                timestamp DEFAULT NULL ,
   executor_id               int DEFAULT NULL ,
   update_time               timestamp DEFAULT NULL ,
-  process_instance_priority int DEFAULT NULL ,
+  process_instance_priority int DEFAULT '2' ,
   worker_group              varchar(64),
   environment_code          bigint DEFAULT '-1',
   dry_run                   int DEFAULT '0' ,
@@ -309,7 +309,7 @@ CREATE TABLE t_ds_error_command (
   start_time                timestamp DEFAULT NULL ,
   executor_id               int DEFAULT NULL ,
   update_time               timestamp DEFAULT NULL ,
-  process_instance_priority int DEFAULT NULL ,
+  process_instance_priority int DEFAULT '2' ,
   worker_group              varchar(64),
   environment_code          bigint DEFAULT '-1',
   dry_run                   int DEFAULT '0' ,
@@ -392,7 +392,7 @@ CREATE TABLE t_ds_task_definition (
   task_type varchar(50) DEFAULT NULL ,
   task_params text ,
   flag int DEFAULT NULL ,
-  task_priority int DEFAULT NULL ,
+  task_priority int DEFAULT '2' ,
   worker_group varchar(255) DEFAULT NULL ,
   environment_code bigint DEFAULT '-1',
   fail_retry_times int DEFAULT NULL ,
@@ -427,7 +427,7 @@ CREATE TABLE t_ds_task_definition_log (
   task_type varchar(50) DEFAULT NULL ,
   task_params text ,
   flag int DEFAULT NULL ,
-  task_priority int DEFAULT NULL ,
+  task_priority int DEFAULT '2' ,
   worker_group varchar(255) DEFAULT NULL ,
   environment_code bigint DEFAULT '-1',
   fail_retry_times int DEFAULT NULL ,
@@ -534,7 +534,7 @@ CREATE TABLE t_ds_process_instance (
   executor_id int NOT NULL ,
   history_cmd text ,
   dependence_schedule_times text ,
-  process_instance_priority int DEFAULT NULL ,
+  process_instance_priority int DEFAULT '2' ,
   worker_group varchar(64) ,
   environment_code bigint DEFAULT '-1',
   timeout int DEFAULT '0' ,
@@ -703,7 +703,7 @@ CREATE TABLE t_ds_schedules (
   release_state int NOT NULL ,
   warning_type int NOT NULL ,
   warning_group_id int DEFAULT NULL ,
-  process_instance_priority int DEFAULT NULL ,
+  process_instance_priority int DEFAULT '2' ,
   worker_group varchar(64),
   environment_code bigint DEFAULT '-1',
   create_time timestamp NOT NULL ,