Objective To observe the change in the prevalence of post-traumatic stress disorder (PTSD) 1 year after trauma exposure and analyze the risk factors of PTSD 1 year after trauma exposure. Methods Convenience sampling was conducted at the initial outbreak of the coronavirus disease 2019 epidemic and 1 year later, respectively. Participants participated in the anonymous online survey. The survey consisted of 2 self-completed questionnaires: 1 collected personal information (gender, age, education level, occupation) and subjective sleep quality; the other is the PTSD checklist (PCL-5) from the Diagnostic and Statistical Manual of Mental Disorders, 5^th edition. Valid questionnaires of 2 091 and 2 092 were respectively retrieved at the initial stage of trauma exposure and 1 year later. Results The prevalence of PTSD at the initial stage of trauma exposure was 5.3% (111/2 091) and 1 year after trauma exposure was 19.1% (399/2 092). Multiple linear regression analysis showed that age (P＜0.01), gender (P＜0.01), and subjective sleep quality (P＜0.01) were risk factors related to PTSD. Conclusions One year after trauma exposure, the prevalence of PTSD increases. Psychological intervention measures should be given at the early stage of trauma exposure, and special attention should be paid to young individuals, women, and those with sleep disorders.