Objective: To assess the nutritional status of primary and secondary school students in Beijing City and to analyze the related factors, so as to provide a scientific basis for improving the nutritional status of primary and secondary school students in a targeted manner. Methods: Based on the 2021 Beijing Student Common Diseases and Health Influencing Factors Surveillance Project, a stratified random cluster sampling method was used to conduct a physical examination and questionnaire survey on 25 487 primary and secondary school students from September to November 2021. The Chi square test was used for comparison of nutritional status detection rates, and disordered multi classification Logistic regression analysis was used to explore the factors associated with students nutritional status. Results: The detection rates of malnutrition, overweight and obesity among primary and secondary school students in Beijing City were 4.7%, 18.0% and 23.8% respectively. The detection rates of malnutrition, overweight and obesity were higher among male students (5.1%, 20.4%, 29.7%) than female students (4.2%, 15.5%, 17.4%) ( χ 2= 12.23, 101.71, 526.99, P <0.01). The detection rate of obesity was higher in the suburbs than urban areas(26.6%, 19.8%), and the detection rate of malnutrition was lower in the suburbs than urban areas (4.2%,5.5%)( χ 2=157.25, 23.61, P <0.01). The results of disordered multi classification Logistic regression showed that the related factors for malnutrition, overweight and obesity were gender, residence, moderate to vigorous exercise ≥60 min per day and lack of sleep( OR =1.70, 1.88,2.48; 1.14, 0.87, 0.67; 0.85, 0.92, 0.81 ; 0.83, 1.08, 1.07); frequency of fried food intake daily was a related factor for overweight ( OR =0.70); whether eating breakfast daily or not was a related factor for overweight and obesity ( OR =0.91, 0.84); academic level (middle and high school) was a related factor for malnutrition and obesity ( OR =1.38, 1.37; 0.77, 1.40)( P <0.05). Conclusions The problem of overweight and obesity among primary and secondary school students in Beijing City continues to be serious, especially among boys and suburban areas. It is recommended that society, schools, families and individuals should work together to improve the nutritional status of primary and secondary school students by adopting a graded and classified approach.