Objective To explore the effect of dietary behavior intervention in preschool children with autism spectrum disorder.Methods A total of 76 preschool children with autism spectrum disorder suffering from eating behavior problems were randomly divided into an experimental group and a control group, with 38 cases in each group.The control group received routine dietary gui-dance, while the experimental group additionally received evidence-based dietary behavior intervention.Results Thirty-six children in the experimental group and 35 children in the control group completed the study.After 12 weeks of the intervention, the subscale score of active eating ability of the experimental group was significantly higher than that of the control group, while its subscale scores of picky eating and bad eating habits, gastrointestinal symptoms and the severity of autism symptoms were significantly lower than those of the control group （all P＜0.05）.Conclusion Implementation of evidence-based eating behavior intervention for preschool children with autism spectrum disorder suffering from eating behavior problems, can effectively improve their eating behavior problems, alleviate gastrointestinal symptoms, and reduce the severity of the disease.