You can enter a post bar at will and find that there is a signature file setting in the post bar setting in the drop-down box of your user name. Choose to add a signature file, then go to your Baidu Space Album to find the picture you want, and then copy and paste the link into the URL that it allows you to enter.

If you don't mind, you can give me your account number and password, and I will help you set it up.