Objective: To investigate the annual trend and influencing factors of screening myopia prevalence among children and adolescents in Tianhe District, Guangzhou from 2021 to 2024, so as to provide a scientific basis for optimizing targeted and precise regional myopia prevention and control strategies. Methods: From 2021 to 2024, a stratified cluster random sampling method was adopted to recruit 10 132 students ranging from senior kindergarten to senior high school from fixed monitoring sites for myopia screening. Additionally, a questionnaire survey on myopia related factors was administered to 7 115 students in grade 4 and above. Generalized estimating equation (GEE) models were used to analyze the annual changing trends and interaction effects, and mixed effects models were performed for sensitivity analysis. Results: The screening myopia prevalence among children and adolescents in Tianhe District from 2021 to 2024 was 58.9%, 57.3%, 56.8%, and 54.7%, respectively, and showed a statistically significant difference ( χ 2=9.06, P <0.05). The prevalence rates among senior kindergarten, primary school, junior high school, regular senior high school, and vocational high school students were 8.7%, 40.7%, 74.3%, 86.7%, and 75.6%, respectively （χ 2= 2 493.11， P <0.05). The prevalence was significantly higher in female students (60.9%) than in male students (53.3%) ( χ 2= 59.22 , P <0.05). GEE analysis showed that male students ( OR =0.59), primary school students ( OR =0.45), those who spent less than 6 hours per day sitting indoors ( OR =0.78), and those who used electronic devices for no more than 2 hours per day ( OR = 0.25 ) all had lower risks of screening myopia (all P <0.05). Students in regular high schools ( OR =2.01), those who engaged in activities inside the classroom during breaks ( OR =1.55), those who engaged in activities outside the classroom but within the school building during breaks ( OR = 1.46), those who never or only occasionally maintained proper reading and writing postures ( OR =1.32), those with less than 2 hours of daily outdoor activity ( OR =1.86), those with both parents being myopic ( OR =2.48), those with only the father being myopic ( OR =1.50), and those with only the mother being myopic ( OR =1.63) all had higher risks of screening detected myopia (all P ＜0.05). Interaction effect analysis revealed annual heterogeneity in the effects of daily outdoor activity time ≥2 h and daily electronic device use time >2 h on screening myopia prevalence (all P ＜0.05). Conclusions The screening myopia prevalence among children and adolescents in Tianhe District, Guangzhou, demonstrates a continuous downward trend. The impacts of daily outdoor activity duration and electronic device usage time on screening myopia exhibit annual heterogeneity. Dynamic and targeted myopia prevention and control strategies should be formulated in accordance with regional demographic features and environmental changes.