In fact, the master's degree is usually three years. In the first year, I studied basic knowledge, and in the second two years, I was mainly responsible for tutor projects and thesis research. However, some majors are quite special, such as Peking University, China University of Science and Technology, Beihang University and so on. Some schools may implement flexibility for 2-3 years.
Most universities have a two-year master's degree, but some universities may offer a three-year master's degree. For example, the master's degree in plant nutrition in China Agricultural University is a three-year program, and the master's degree in journalism and communication in Soochow University was announced to be changed to a three-year program last year.
Generally speaking, the defense of doctoral thesis should be completed within 1 year after the applicant has passed all the course examinations, during which the school should appoint a doctoral tutor to give necessary guidance to the applicant's thesis. You can graduate if you pass the doctoral thesis defense, so it usually takes 4-5 years to get the certificate.