Based on the definition of recreational sports activities, this paper summarizes the role of recreational sports activities on adolescents’ social competence and initially conducts the design of related survey questionnaires. Then the scientific feasibility of the questionnaire is examined using the reliability test method. The online survey distribution was used to obtain initial data for this paper’s study. The influence of leisure sports activities on adolescents’ social competence was investigated using Spearman’s correlation coefficient and regression model. It was explored that there was a significant positive correlation between the dimensions of leisure sports activities and the dimensions of adolescents’ social competence, satisfying Sig<0.05, in addition to which it was concluded that cooperative spirit = 21.714 + 0.616*facilities + 0.445*time + 0.749*atmosphere + 0.637*cognition + 0.843*interest, and that the independent variable had 78.9% explanatory power for the dependent variable. This study conducted quantitative research on the social competence of adolescents through recreational sports activities using questionnaire scales and mathematical analysis models.