Objective: To explore the relationship between physical activity, screen time, sleep duration and physical health of middle school students, to provide reference for physical health intervention in middle school students. Methods: A total of 1 614 students from 12 middle schools in Tianjin were investigated by stratified random cluster sampling. According to the "Canadian 24 Hour Movement Guidelines for Children and Youth", participants were divided into 4 groups: "full qualified group", "2 item qualified group", "1 item qualified group" and "unqualified group". Binary Logistic regression analysis was used to predict physical health risk. Results: Only 5.2% boys and 4.2% girls met the standard in all three behaviors, and 16.4% boys and 16.3% girls failed to meet the standard in all three behaviors. The excellent and good rates were 77.7% and 71.8% in the 2 item qualified group and the full qualified group, respectively. The physical health risk of middle school students with insufficient physical activity was 1.76 times higher than that of those who achieved the standard, and the physical health risk of students with too much screen time was 1.34 times higher than that of those who achieved the standard. Physical health risk of middle school students with insufficient sleep duration was 2.86 times higher than that of those who achieved the standard, and the risk of overweight and obesity was 1.49 times higher than that of those who achieved the standard ( P <0.05). Compared with the middle school students who achieved all the standards, physical health risk of unqualified group was 3.63 times, and that of the 1 item qualified group was 2.10 times ( P < 0.01 ). Conclusion Middle school students meet two or more recommendations in physical activity, screen time and sleep duration are more likely to have better physical health and lower risk of overweight and obesity. The findings suggest that students should engage in active sports to increase the high intensity of physical activity, reduce screen time, maintain a healthy sleep habits, in order to obtain better health level.