After logging into the qq main interface, click the icon of space, which is star-shaped.

After entering the home page of the space, click the setting icon in the upper right corner of the space, a pinion-shaped icon.

After entering the space settings, select the synchronization settings option.

Check the two options in the synchronization settings "Synchronize QQ signature to space talk" and "Synchronize space talk to QQ signature" and save them.

Click-Who can view my space in permission settings? Select the category you want to restrict, such as -QQ friends, only your QQ friends can see your space and signature, but strangers can't. You can also choose "only yourself". Only you can see your own space and signature, but others can't. After selecting the restricted category, click-Save, so that the signature you don't want others to see is set successfully.