In recent years, although the overall physical health of Chinese students has shown an upward trend, the substantial decline in student physical fitness has been basically curbed. Most of the physical health indicators of students are steadily improving, but there are still many problems that need to be vigilant. In order to solve the problem of the decline of the physical health of primary school students, it is very important to construct a teaching system based on big data and artificial intelligence to promote the physical health of primary school students. This article aims to study from the actual situation and find scientific and reasonable methods to improve the physical health of primary school students. This article uses the literature method, questionnaire survey method, mathematical statistics method, and other research methods to analyze and study the current physical condition of the interviewed students and the actual influencing factors by taking students from 5 domestic primary schools as the research object. It is concluded that more than 90% of primary school students in Haidian District, Beijing, have good physique and physical development. The development level of strength and flexibility is gradually improved, but the speed and endurance quality are on the decline, especially the endurance quality of primary school boys has declined the most. Lack of good exercise habits, insufficient exercise time and exercise efficiency, and lack of appropriate exercise volume and necessary exercise intensity are currently the most important factors affecting the physical health of primary school students. The physical problems of primary school students are not caused by a single factor, but the result of multiple factors. This article puts forward a number of suggestions for the above situation and problems to be solved urgently.