Objective: To explore the relationship between sleep and exercise among grade 1-6 students in a certain city during the period of home based online courses in the epidemic, and to provide reference basis for the government and relevant departments to make relevant policies on student health promotion. Methods: From April 22 to May 14 in 2020, 24 452 primary school students were selected by stratified cluster random sampling method to network questionnaire survey, which included general situation, sleep time,and exercise. Results: Totally 21.6% of primary school students participated in low intensity exercise, 9.4% in moderate intensity exercise and 5.8% in high intensity exercise every day. Less than 10% of the students participated in all types of intense sports for more than 30 minutes each time. The report rate of sleep deprivation among students in grades 1 to 6 was 22.5%, 25.5%, 28.9%, 31.3%, 35.0%, 39.9%, respectively(χ 2=350.75, P<0.05). Multivariate Logistic regression analysis showed that after adjusting for gender, grade, oneness and other factors, high intensity exercise was negatively correlated with sleep deprivation(OR=0.91, 95%CI=0.86-0.97). Conclusion Insufficient sleep is common among primary students, and appropriate amount of high intensity exercise is a favorable factor to ensure adequate sleep time in primary school students.