Objective: To explore the relationship between school sports environment and physical activity levels of middle school students, so as to provide theoretical and empirical support for optimizing school sports environment and enhance adolescent physical activity. Methods: Using multi-stage random cluster sampling, from September to December 2023, 1 329 junior and senior high school students from Xuancheng City of Anhui Province, Lianyungang City of Jiangsu Province, Wuhan City of Hubei Province, Qiqihar City and Suihua City of Heilongjiang Province, and Shenzhen City of Guangdong Province were selected. The International Physical Activity Questionnaire-Short Form (IPAQ-SF) assessed students physical activity levels, and the questionnaire on the characteristics of school sports environment was developed to evaluate the factors of school sports environment. Multivariate ordered Logistic regression was performed to analyze the correlation between school sports environment factors and physical activity levels, and the analytic hierarchy process determined the weight of key influencing factors. Results: The results showed that weekly vigorous physical activity time was [60 (25, 90)] minutes, moderate physical activity time was [60 (30, 90)] minutes, light physical activity time was [105 (40, 200)] minutes, and sedentary behavior time was [ 3 300 (2 100, 4 500)] minutes, only 10.53% of the students met World Health Organization physical activity recommendations, and 89.69% of the students averaged >8 h daily sedentary time. Multivariate ordered Logistic regression showed that adequate sports equipment significantly promoted physical activity across all intensities and reduced sedentary time ( OR = 4.97, 11.54, 4.03, 0.11); diverse sports activities improved vigorous and moderate physical activity while reducing sedentary time ( OR =4.20, 14.06, 0.17); and peer encouragement was associated with increased low-intensity physical activities and decreased sedentary time ( OR =10.40, 0.15)( P <0.05). The analytic hierarchy process weighting analysis identified the top three influential factors related to physical activity among middle school students: sufficient sports equipment, varied physical education activities, frequent peer encouragement, the influence weight accounts for 23.55% , 14.18% and 11.77% of the total, respectively. Conclusion Key school sports environmental factors for adolescent physical activity level include ensuring adequate sports equipment and class availability, diversifying activity content, fostering peer support, and cultivating an active sports culture and a comprehensive approach encourage students participation in extracurricular physical activities.