Objective: To investigate abnormal spinal curvature among primary and secondary school students in Sichuan Province, so as to provide evidence for scientific prevention. Methods: Using a stratified cluster random sampling method, a total of 210 713 students of grade 4 to grade 12 from 21 cities (prefectures) in Sichuan Province were selected for spinal curvature screening and questionnaire survey from September to November 2022. Chi-square test and multivariate Logistic regression model were used to analyze the influencing factors of abnormal spinal curvature. Results: The detection rate of abnormal spinal curvature was 3.42%, with urban areas (4.54%) higher than that in suburban areas(2.57%), girls (3.86%) higher than that in boys(2.98%), high school students (4.70%) higher than that in middle school students (3.80%) and elementary school students(2.21%), the differences were statistically significant ( χ 2=606.96, 123.81, 645.24, P <0.01). Multivariate Logistic regression analysis showed that urban area, junior and senior high school, girl, carrying backpack on one shoulder, desks and chairs adjusted for student height less than ≤1 time every school year, moderate-to-vigorous physical activity less than 1 h per week, and indoors sedentary time more than 10 h/d were positively associated with abnormal spinal curvature ( OR=1.72, 1.75, 1.87, 1.26, 1.09, 1.07, 1.10, 1.25 , P <0.05). Conclusion The detection rate of abnormal spinal curvature of primary and secondary school students may be affected by the urbanicity, educational stage as well as gender in Sichuan Province. More attention should be paid to urban high school girls, and targeted strategies should be explored to reduce the incidence of abnormal spinal curvature.