Objective: To analyze the prevalence and determinants of comorbid overweight/obesity and elevated blood pressure among primary and secondary school students in Yangzhou City, and to explore the association between sleep patterns, eating behavior and the comorbidity of overweight/obesity and elevated blood pressure, so as to provide reference for developing prevention strategies targeting common comorbidities in students. Methods: By using stratified cluster random sampling, a total of 8 735 primary and secondary school students were selected from 36 schools in six counties of Yangzhou from October to November 2023. Students underwent physical examinations and a questionnaire survey was conducted using the questionnaire on students health status and influencing factors. The Chi square test was used to compare the detection rate of comorbid overweight/obesity and elevated blood pressure in different groups of primary and secondary school students. The Logistic regression model was used to explore the association between sleep and dietary behaviors and their combined effects and coexistence. Results: The detection rate of comorbid overweight/obesity and elevated blood pressure among primary and secondary school students in Yangzhou was 9.85%, which was higher among boys (12.14%) than girls (7.59%)( χ 2=50.86, P <0.01). After controlling for gender, residence, educational stage, parental education, smoking, drinking, and moderate to vigorous exercise, multivariate Logistic regression analysis showed that irregular breakfast consumption and inadequate daily sleep were associated with a higher risk of comorbidities compared with regular breakfast consumption and adequate daily sleep among overall and primary school students (overall: OR =1.52, 95% CI =1.18- 1.96 , primary school students: OR =2.79, 95% CI =1.61-4.82)(both P <0.05). From the perspective of primary school students of different genders, the risk of comorbidities in girls who consumed breakfast irregularly and had inadequate daily sleep was 3.59 times higher than that in girls who consumed breakfast irregularly and had inadequate daily sleep (95% CI =1.65-7.82, P <0.01). Conclusion The sleep patterns and breakfast behaviors of primary and secondary school students are found to be associated with comorbid overweight/obesity and elevated blood pressure, especially in primary school girls.