@aric now just "profile" and "notice" tables use Myisam engine,others all use InnoDB. And I have tried to switch "profile" and "notice" tables into InnoDB engine, the Problem persists.
I have a problem to be resolved:
I can not use chinese tag in my website,when i use chinese character as a tag,it appears as garbled,and I found it did not write into the mysql database.