In The health of children and adolescents is an indispensable part of building a healthy city. This paper describes the monitoring results of common diseases among students and school environmental sanitation in Beijing in 2021，analyzes the relevant influencing factors，and analyzes the main common diseases such as myopia and obesity among children and adolescents in Beijing，which will help to further implement the monitoring task，take targeted interventions，and promote the health of children and adolescents. The monitoring found that the detection rate of poor vision of students was 67.1%，the detection rate of myopia was 56.1%，the total detection rate of overweight and obesity was 41.1%，and the prevalence rate of permanent teeth caries was 27.4%，both at a high level. The situation of prevention and control of common diseases among students is still very serious，health risk issues need to be paid attention to，and the details of school health work still need to be improved. In response to the existing problems，Beijing has carried out six major actions，including the action of experts entering the campus，the action of popularizing school health standards，the activity of health month for primary and secondary students，the action of improving school teaching and living environment，the action of healthy parents and the action of caring for key groups，and carried out various common disease prevention and control activities. At the same time，Beijing has actively created myopia prevention and control measures with unique Beijing characteristics to promote the improvement of students’ health level.