The purpose of the current study is to understand the characteristics of AIDS patients combined with syphilis in Shanghai in recent years, explore the influencing factors of AIDS patients with syphilis, and provide a scientific basis for the prevention and control of such diseases in Shanghai. Through the collection of relevant data on the diagnosis of AIDS combined with syphilis cases discharged from the Shanghai Public Health Clinical Center during 2013 to 2019, the case characteristics and trend of changes were analyzed, and the relevant factors affecting AIDS patients with syphilis were studied. The results showed that the prevalence rate of syphilis among AIDS patients in Shanghai was 10.55%, The overall infection rate of AIDS complicated with syphilis in this hospital showed an upward trend from 2013 to 2019 (χ2＝17.640，P<0.05). July-August is the peak period of annual admissions. The patients were mainly from local residents (55.49%), the male to female ratio was 14∶1, and the average age was (38±12) years old. Through logistic regression analysis, it was found that the factors affecting AIDS and syphilis were gender, age, source of cases, and CD4^＋T lymphocyte count. Among them, local, 21-40 years old, male and CD4^＋T lymphocyte count ≤500 /μL are high risk factors for AIDS patients with syphilis infection. This study suggests that the number of AIDS-combined syphilis infection cases in Shanghai from 2013 to 2019 is on the rise. The key population for prevention and control is Shanghai’s young and middle-aged male residents. The ability to actively monitor such populations should be improved, and screening efforts should be increased as well as good health education. The key prevention and control period is July and August each year, and precise prevention and control are expected to achieve obvious results.