Objective: To understand changes and health equity of low vision in children and adolescents in Chongqing, and to provide reference for student myopia prevention and control. Methods: Using longitudinal studies, all school students in grades 1 to grade 12 in Chongqing were examined for visual acuity during 2018 to 2021, and the prevalence as well as changes of low vision were analyzed. In 2021, stratified random sampling was used to evaluate the health equity of uncorrected visual acuity and diopter(spherical equivalent, SE). Results: The prevalence of low vision for children and adolescents in Chongqing from 2018 to 2021 was 54.12%, 58.17%, 60.03% and 58.20% respectively. Low vision showed an increasing trend in the first three years and decreased by 1.83% in 2021 as compared with 2020( χ 2 trend =13 870.45, P <0.01). The difference in the detection rate of poor vision among students in different grades was statistically significant( χ 2=17 396.36, 2 093.95, 771.87, P <0.01). From 2018 to 2021, the detection rate of low vision in girls was higher than that of boys( P <0.01). The Gini coefficient was 0.054 57 for uncorrected visual acuity in urban area, higher than in rural areas (0.035 94). Meanwhile, the Gini coefficient of urban and rural SE was 0.065 82, higher than the country (0.049 30). The results showed that myopia in children and adolescents was more uneven in urban areas. Conclusion The adjustment of myopia prevention and control strategies in the late stage of the novel coronavirus pneumonia epidemic is related to the reduction of the detection rate of poor vision in children and adolescents in Chongqing. Low vision varied by grade and gender, suggesting tailored myopia prevention and control strategy. The detection rate of poor vision in cities is more uneven than in rural areas, and different myopia prevention and control measures need to be implemented according to regional characteristics.