HIV postexposure prophylaxis (PEP) has been prescribed to non-occupational people in recent years, but the implementation of PEP in China is still unclear. This study sought to examine the PEP use rate and factors associated with PEP in Men who have sex with men (MSM). We recruited HIV-negative MSM through offline methods from 2018 to 2020 in Shenzhen, China. Overall, PEP use increased from 3.92% to 2018, 5.73% in 2019, and 10.29% in 2020. Among 2833 participants who reported their most recent questionnaire, factors associated with PEP use included residence in Shenzhen less than 1 year, sexual intercourse with women, preferred way of finding sexual partners in MSM venues, multiple sexual partners (>= 2), condom use, lubricant use, viagra use, less use of rush popper, HIV-related services and interest in initiating Pre-exposure prophylaxis (PrEP). The implementation of the PEP plan should focus on the groups that may be at risk of HIV infection and their continued risky behaviours. For the inappropriate use of PEP, PEP publicity should guide MSM to choose regular hospitals and strengthen HIV testing before and after PEP.