The purpose of this study was to apply the planned behavior theory to explore the behavior intention and the actual behavior of the junior high school students participating in the relay race of the class brigade. Taking the students of national Datong junior high school in Changhua County of Taiwan as the research object in 2018, the questionnaire was sampled and distributed, and 904 valid questionnaires were obtained. Structural equation model (SEM) analysis using AMOS 19.0 statistical software shows that the compatibility of each model is good. The results are found as follows: The behavior attitude and subjective norm of the junior high school students participating in the relay competition of the class brigade have a significant positive impact on the behavior intention, and indirectly affect the actual behavior by the behavior intention. Among them, the positive influence of teachers in the subjective norm on the named group students is significantly higher than that of the unnamed group students. There is a positive correlation between the behavior attitude, subjective norm, and perceived behavior control of the junior high school students participating in the relay competition of the class brigade. The perceived behavior control of the junior high school students participating in the relay competition of the class brigade does not have a positive impact on the behavior intention and the actual behavior. Finally, relevant suggestions are put forward for the results of this study, as a reference for future relevant units to promote and guide students to participate in the brigade relay competition.