Objective: This study conducts a Meta analysis on the epidemiological studies of obesity and autism spectrum disorder (ASD) in order to explore the relationship between autism spectrum disorder and obesity in children and adolescents, and to provide some guidance for improving the quality of daily life of children and adolescents with ASD. Methods: PubMed and CNKI (January,2010-January,2022) were systematically searched for literature related to autism spectrum disorders reported the or value by Meta analysis, and compared the weight, BMI acquisition method. Results: A total of 11 literatures were selected for analysis. The total sample included 336 830 participants, including 58 187 patients with ASD and 278 643 patients with normal development. Through Meta analysis, children and adolescents with ASD had a higher risk of obesity than normal people ( OR=1.80, 95%CI = 1.74 -1.86). when stratified by BMI acquisition, autistic patients with BMI obtained from objective measurement, medical records and parents reports had a higher risk of obesity than normal people, and the OR value (95% CI ) was 1.43(1.04-1.96),5.23( 4.44- 6.16),2.57(1.79-3.69). When stratified by age, children and adolescents with ASD aged 14 to 20 years had a higher risk of obesity than normal people. The OR value (95% CI ) was 2.19(1.21-3.94). Conclusion Compared with healthy peers, children and adolescents with ASD have a higher risk of obesity. ASD patients need guidance in diet and physical activity, especially in adolescence, to prevent obesity or diseases caused by obesity.