Abstract: Sleep is crucial for students' mental and physical wellbeing. However, students in the primary and secondary school are experiencing a sleep crisis, with a possible stratification based on family socioeconomic status. This study utilized data from CFPS2018 to analyze the relationship between family socioeconomic status and sleep among primary and secondary school students in China. Two mediating mechanisms were proposed: attending tutoring classes and parents' sleep patterns. The results indicated that children from advantaged families were at a higher risk of insufficient sleep. The mechanisms were that these children were more likely to participate in tutoring classes, and their parents were more likely to have a delayed bedtime, thereby reducing their sleep duration. Therefore, policies aimed at reducing the educational burden should be more contextual and targeted.