Objective: To determine the association between the intake of five major types of prepackaged foods and the growth and development of school aged children, so as to provide a theoretical basis for guiding school aged children and their parents to make healthy prepackaged food choices. Methods: Based on data from the South West China Childhood Nutrition and Growth Cohort (SCCNG), 381 children (6-11 years of age) were selected by stratified cluster sampling. Dietary intake and pubertal development were collected using questionnaires, and anthropometric measurements were obtained. Children were followed up until November 2022. Binary Logistic regression models were used to analyze the prospective association between prepackaged food intake and the growth and development of school aged children. Results: The total intake of the five major types of prepackaged foods was 316.1 (197.1,501.4) g/d. After 2 years of follow up evaluations, 16.5% of school aged children were shown to be overweight and obese. Early spermarche occurred in 12.6% of boys and early menarche occurred in 15.4% of girls. The following findings were suggested after adjusting for the mothers education level, average gross monthly family income, whether or not the family had one child only, geographic area of residence, body mass index Z score, average duration of daily exercise, and total dietary energy intake: convenience food intake might increase the risk of early spermarche ( OR =9.37); fruit and vegetable intake might decrease the risk of early spermarche and menarche ( OR =0.33,0.17); and fish, poultry, meat, and egg intake might increase the risk of early menarche ( OR =7.59)( P <0.05). Intake of the five types of prepackaged foods was not associated with being overweight or obese after adjusting for confounders ( OR =1.40, 0.57, 0.73, 1.33,1.57, P >0.05). Conclusions The relationship between intake of the five major types of prepackaged foods and pubertal development is inconsistent and no significant correlation was detected between the intake of prepackaged foods and overweight or obese children. Nutrition education should be strengthened to help children and their parents choose healthy prepackaged foods.