Men who have sex with men (MSM) carry the burden of HIV infection in China. Outside of China, a history of childhood sexual abuse (CSA) has been associated with HIV-related risks (behavioral, sexual, and mental health outcomes) among MSM. We therefore evaluated the relationship between CSA and these HIV-related risks among MSM in China. Cross-sectional data were collected via a survey from gay websites and social networking applications from MSM in 30 provinces in mainland China during a 3-month period in 2014 and 2015. Overall, 999 screened MSM who responded to questions on CSA were included. Multinomial logistic regression models—adjusted for sociodemographic confounders—showed that men who reported experiencing regular CSA and contact CSA, respectively, were more likely to use substances (adjusted odds ratio [AOR], 1.91; 95% confidence interval [CI] 1.39–2.62 and AOR, 1.70; 95% CI 1.25–2.31), had a history of sexually transmitted infections (AOR, 1.81; 95% CI 1.29–2.55 and AOR, 1.65; 95% CI 1.18–2.96), had more male sexual partners (AOR, 1.06; 95% CI 1.04–1.09 and AOR, 1.05; 95% CI 1.03–1.08), engaged in more condomless sex with men (AOR, 1.89; 95% CI 1.39–2.56 and AOR, 1.72; 95% CI 1.29–2.30), and experienced more psychological distress (AOR, 1.05; 95% CI 1.02–1.08 and AOR, 1.05; 95% CI 1.03–1.08). Both frequent and contact forms of CSA were positively associated with HIV-related risks among MSM, suggesting that general CSA prevention strategies and interventions are needed to support this population.