Objective: To understand sexual and reproductive health knowledge, access to sexuality education and associated factors among secondary vocational school students in Shanghai Municipality and Shaanxi Province, so as to provide a scientific basis for conducting sexuality educaiton in vocational schools. Methods: A crosssectional survey was conducted among 3 180 students in grades 1-3 selected by cluster sampling during April to June 2021 in six secondary vocational schools from three cities of Shanghai and Shaanxi (Shangluo, Ankang, Baoji). Participants were investigated through online questionnaire survey, inlcuding demographic characteristics, household information, sexual health at home and school, knowledge on sexual and reproductive health. Both t test and Chisquare test were used for group comparisons, and multivariate ordial Logistic regression was used to explore possible risk factors for sexual and reproductive health score in quartiles. Results: Respondents average score was (51.36±21.61), with the highest score on sexual harassment/sexual abuse (66.45±42.27) and the lowest score on reproduction and physiology (47.67±31.94) and contraception (43.85±26.81). Although significant differences were observed between two study sites, the primary source of knowledge in both sites was schools/teachers, followed by the Internet or friends; the main theme of school sexuality education was puberty development and health care (more than 80%); the most frequently reported topic between respondents and their parents in both sites was interpersonal relationships (more than 55%), and there were significant differences in the reporting rates of secondary vocational school students between the two regions(χ2=28.56，32.02，P<0.05). The results of multivariable Logistic regression analysis showed that residential area, gender, grade, registered residence, number of sexual related topics communicated with parents, number of subjects received from school sexuality education, and reported information sources from classmates/friends, books/magazines/newspapers, internet and communities were related to knowledge level of respondents (OR=1.62, 0.72, 1.20, 1.58, 2.09, 1.17, 1.18, 1.66, 1.62, 1.69, 1.22, P<0.05). Conclusions Vocational students of Shanghai and Shaanxi have poor sexual and reproductive health knowledge and limited access to school and family sexuality education. It is necessary to strengthen sexuality education for secondary vocational school students.