Log in to QQ space, click the gear button = Space Settings = Synchronization Settings = Synchronization QQ Signature, and check "Synchronization Space Chat QQ Signature" to save. If you don't want to synchronize, just uncheck it.
Note: After the setting is successful, your comments in the space will be displayed to QQ signature synchronously, but information such as pictures and videos will not be synchronized (except comments made by clients such as mobile phones).