方法一： 删除原来的字段重新添加
Alter table talbeName Drop Column ColumnName
Alter table talbeName Add ColumnName Int IDENTITY(1,1)方法二： 使用命令进行修改
dbcc checkident('test',reseed,0)
检查自动增加ID: dbcc checkident (表名TableName)建表事例
create table tb(id int identity ( 1 , 1 ),name varchar ( 10 ))
insert into tb(name) select ' abc '
insert into tb(name) select ' sfd '
insert into tb(name) select ' efawe '
insert into tb(name) select ' asdf2 '
insert into tb(name) select ' efw '
insert into tb(name) select ' afsd '
insert into tb(name) select ' asdf2 '
insert into tb(name) select ' 2fsf '
insert into tb(name) select ' cawe '
insert into tb(name) select ' sdf2qe '
go
select * from tb来源1：http://soft-development.iteye.com/blog/792088
来源2：https://blog.csdn.net/yanwu616/article/details/2874345?utm_source=blogxgwz8