Can I go back to China without brp?

You can go back to China. If you stay in the UK, you need to reissue the BRP.

Brp's English full name is biometric residence permit, and Chinese commonly known as biometric information card.

This kind of visa is mainly for international students in the UK. This card will contain your fingerprint and visa information. On the day of face-to-face interview, the applicant needs to take photos directly with his fingerprints, and the photos will be recorded as information in the card. If you mail your application in the UK, UKBA will send you a letter after receiving the application form, asking you to go to a nearby place where fingerprints can be printed (such as some post offices). This process only takes 10 minutes. No fingerprints will be issued on the same day after pressing the ID card.