Under normal circumstances, postgraduate entrance examination only requires a bachelor's degree or above, but there are indeed some postgraduate colleges and universities that have requirements for CET-4 and CET-6, degree certificates or papers. For example, Peking University, Tsinghua University, Beijing University of Posts and Telecommunications, Beijing University of Technology, and China Agricultural University all require CET-4 equivalent qualifications to apply for the exam and publish papers. (The content is for reference only, subject to the information released by official website)
Candidates only need to have a bachelor's or junior college diploma to register. However, some schools have revised the conditions for entering the exam, requiring a bachelor's degree to take the postgraduate entrance examination. This kind of school will clearly put forward the need for a degree certificate in the enrollment brochure. If not, you can consider not needing a degree certificate. Everyone should know about the specific registration conditions of the admissions institution before applying for the exam. Moreover, the results of the first test of postgraduate entrance examination are the most important. Even if you don't have a degree certificate, it won't have a great impact on you if you get high grades in the initial test.