The main purpose of this study is to understand the factors affecting adolescents' eating out behavior, as well as to develop scientific principles for selection of factors affecting adolescents' eating out behavior. According to literature review and expert questionnaire survey, this study obtained the factors affecting adolescents' choice to eat out, and used these factors to establish the Analytic Hierarchy Process (AHP) hierarchical structure. This study used AHP to calculate the weight of factors affecting adolescents' choice to eat out, as well as to develop the principles for selection of factors affecting adolescents' eating out behavior. The research results can be provided as important reference for curriculum design and content of nutrition education and consumer education for adolescents, and suggestions on relevant planning can be provided for administrative units and health units.