Objective: To investigate the correlation between school bullying and depressive symptoms comorbidity and dietary patterns among middle school students in Inner Mongolia Autonomous Region from 2021, so as to provide reference for the prevention of school bullying and depressive symptoms. Methods: In September 2021, stratified random cluster sampling was used to select 87 414 middle school students in 12 leagues in Inner Mongolia Autonomous Region. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to assess depression, and the bullying was determined according to the items related to bullying in the program of Chinese National Surveillance on Students Common Diseases and Risk Factors. Results: In 2021, the detection rate of depressive symptoms among middle school students in Inner Mongolia Autonomous Region was 15.24%, school bullying was 3.02%, and the co-occurrence of school bullying and depression was 1.64%. Binary Logistic regression analysis showed that junior high school students ( OR =1.52) and girls ( OR =1.10) were more likely to suffer from comorbidity of school bullying and depression ( P < 0.05). Eating fried food less than one and more than once a day, smoking and drinking were positively correlated with school bullying and depression comorbidity ( OR =2.15,2.11,2.14,1.70, P <0.05). Conclusion The combination of bullying and depression among middle school students in Inner Mongolia Autonomous Region is affected by various dietary methods. In terms of diet, reducing the intake of fried food, no smoking, no drinking can effectively reduce the incidence of co-occurrence school bullying and depression.