Cultivating students' self-management ability is the requirement of social development and the progress of the times to school education, and it is also the need for students' growth. For middle school students in adolescence and undergoing tremendous changes in their body and mind, its significance is even more prominent. As an element of direct contact with students, activities play an irreplaceable role in cultivating students' self-management ability. Nanjing Yutong Experimental School has added a self-management course to its teaching plan. Through the development of diversified activities, goals are achieved in specific activities, and the overall development of students has been completed. Taking the school's practical activities as an example, this paper attempted to use the concept of activity teaching to explain better how the school develops self-management of middle school students based on students' development and creates activities suitable for students' growth to realize better students realize self-management in activities.