You don't need to send papers when you graduate from Peking University.
What you want to ask is, do you need to send papers after graduation from Peking University? Need. According to the inquiry in official website, Peking University, it is a general requirement for doctoral students to publish their graduation thesis, which is one of the important means of academic exchange and knowledge dissemination. By publishing papers, graduate students can show their research achievements and contributions to experts and scholars in academia and related fields, and promote academic exchanges and cooperation.