Objective: To examine the association between sexual orientation and high risk sexual behaviors and its sex differences among college students, so as to provide a theoretical basis for intervention and controlling of high risk sexual behaviors of the college students. Methods: From November 2020 to May 2021, 1 920 college students among four universities in Hubei Province were recruited by multi stage stratified random cluster sampling, and their sexual orientation and the frequency of high risk sexual behaviors were investigated by a self designed questionnaire. And then analyzed the association between sexual orientation and high risk sexual behaviors and its sex differences by using Chi square test and Logistic regression analysis method. Results: The prevalence of sexual behaviors was 18.2%, the prevalence of high risk sexual behaviors was 7.2%, and the prevalence of high risk sexual behaviors was higher among non heterosexuals(13.5%) than among heterosexuals (6.7%),the prevalence of high risk sexual behaviors was higher among males (9.2%) than among females(5.3%)，and the differences were statistically significant( χ 2=9.40, 10.77, P <0.01). Logistic regression analysis showed that the association between sexual orientation and high risk sexual behaviors was not statistically significant( OR=1.52, 95%CI=0.83-2.80, P >0.05). However, stratified analysis by sex revealed that among male students, the risk of high risk sexual behaviors was 3.57 times higher among non heterosexuals than among heterosexuals( OR= 3.57 , 95%CI=1.52-8.41, P <0.01), while among female students, the association between sexual orientation and high risk sexual behaviors was not statistically significant( OR=0.48, 95%CI=0.15-1.57, P >0.05). Conclusion There are sex differences in the relationship between sexual orientation and high risk sexual behaviors among college students. Male non-heterosexuals are at higher risk for high risk sexual behaviors than male heterosexuals. Therefore, prevention and interventions for high risk sexual behaviors among college students should focus on gay and bisexual men so as to reduce the occurance rate of their high risk sexual behaviors.