Objective: To evaluate the prevalence and consistency of screening myopia, non-cycloplegic myopia and cycloplegic myopia in children and adolescents, and to provide references for exploring the factors affecting the consistency of different definition methods. Methods: A total of 3 868 children and adolescents aged 6 to 17 years from seven schools were included in a school based cross sectional study in Shandong Province in September 2020. The prevalence of screening myopia, non cycloplegic refraction, and cycloplegic refraction at different ages and all children and adolescents were analyzed. With cycloplegic spherical equivalent ≤-0.50 D as the gold standard for myopia, and Kappa test and area under the ROC curve were used to evaluate the consistency. Results: The prevalence of cycloplegic myopia and screening myopia were 36.7% and 38.3% among children and adolescents. The prevalence of non cycloplegic myopia was 62.4%, which was significantly higher than screening myopia and cycloplegic myopia two methods in primary and junior high schools. Among 3 868 subjects, there were 3 628 (93.8%) subjects with screening myopia and 2 862 (74.0%) subjects with non cycloplegic myopia who were consistent with the gold standard for myopia. The Kappa values of screening myopia and non cycloplegic myopia were 0.87 and 0.51, and the area under the ROC curve was 0.94 (95% CI =0.93-0.95) and 0.79 (95% CI =0.78-0.81). Compared with other groups, children and adolescents aged 8 to 17 years, in junior or high school, urban residence, better presenting distance visual acuity, and astigmatism ≤1.50 D had a higher consistency in the application of screening myopia ( P <0.05). Conclusion The consistency between screening myopia and cycloplegic myopia is high, and the consistency between non cycloplegic objective myopia is low.