Objective To explore the prevalence and influencing factors of mental sub-health among adolescents of different genders in Anhui Province. Methods From October 2020 to January 2021， four township middle schools and four urban middle schools in three cities of Chaohu， Xuancheng， and Tongling in Anhui Province were selected， and students from two classes were randomly selected from each school as the research subject. The general information， social support， and mental sub-health of adolescents with different genders were compared using the General Information Questionnaire， Social Support Rating Scale （SSRS）， and Mental Sub-health Questionnaire. Multivariate Logistic regression was used to analyze the influencing factors of mental sub-health among adolescents of different genders. Results A total of 900 questionnaires were distributed offline， and 834 valid questionnaires were collected， with an effective response rate of 92.67%. The incidence of mental sub-health among 834 adolescents was 25.78% （215/834）， among which the incidence of mental sub-health among female adolescents was 28.95% （119/411）， which was higher than that of male adolescents ［22.70% （96/423）］， and the difference was statistically significant （χ2 =4.268， P=0.039）. There were statistically significant differences in parental marital status， boarding at school， being left behind， subjective support dimension score， and utilization of support dimension among male adolescents with different mental health states （all P＜ 0.05）. There were statistically significant differences in boarding at school， being left behind， objective support dimension score， subjective support dimension score， and utilization of support dimension score among female adolescents with different mental health states （all P ＜ 0.05）. Multivariate Logistic regression showed that being left behind was a risk factor for mental sub-health among male adolescents ［OR=2.200， 95%CI （1.259， 3.844）， P=0.006］， while high subjective support scores ［OR=0.920， 95%CI （0.850， 0.995）， P=0.036］ and high utilization of support scores ［OR=0.783， 95%CI （0.681， 0.900）， P=0.001］ were protective factors for mental sub-health. Among female adolescents， boarding at school was a risk factor for mental sub-health ［OR=2.023， 95%CI （1.105， 3.706）， P=0.022］， while high subjective support scores ［OR=0.895， 95%CI （0.829， 0.965）， P=0.004］ and high utilization of support scores ［OR=0.779， 95%CI （0.680， 0.892）， P ＜ 0.001］ were protective factors for mental sub-health. Conclusions The incidence of mental sub-health among male adolescents in Anhui Province is lower than that of female adolescents. Being left behind can increase the risk of mental sub-health among male adolescents， while boarding at school can increase the risk of mental sub-health among female adolescents. The higher the subjective support and its utilization， the lower the risk of mental sub-health in adolescents.