Objective To explore the application effect of online open course teaching in sexual health education of higher vocational students. Methods In January 2020, 1025 students who volunteered to participate in online courses in our school were given the "Adolescent Sexual Psychology Scale", and then a three-month systematic online course study was conducted. The same set of test papers were tested before and after learning, and the test results were used to compare the acquisition of sexual knowledge before and after learning. After the end of the course, a thematic discussion was initiated to explore the influence of students ' sexual attitude and sexual self-protection after learning sexual knowledge. At the same time, a course satisfaction questionnaire was issued to understand students' satisfaction with learning sexual health knowledge in the form of online open courses. Results The subjects' access to sexual health knowledge was diverse, among which the top three were Internet, novels, television and other media; students had certain sexual knowledge before online learning, but their sexual attitude, sexual behavior and sexual self-concept needed to be improved. Through 3 months of online open course learning, students' access to sexual knowledge was improved; the scores of sexual knowledge assessment after learning were higher than those before learning, and the difference was statistically significant (P <0.05). The vast majority of students were satisfied with the teaching mode of sexual health education in online open courses and were willing to continue learning. Conclusion The application effect of online open course teaching in sexual health education of higher vocational students is definite, which effectively improves the acquisition rate of students' sexual knowledge, affects students' sexual attitude and sexual self-concept, and students are willing to accept it, with good teaching effect.