This research aims to investigate the application of the transtheoretical model in the fields of management, psychology, and health behavior, with a specific focus on gaining a profound understanding and conducting quantitative studies. Proposed by American psychologists James O. Prochaska and Carlo C. DiClemente in 1983, the transtheoretical model has evolved into a crucial theory in the realm of management. It seeks to dissect the various stages individuals undergo when attempting to alter unhealthy behaviors, serving as a basis for formulating intervention strategies. The research delves into the application of the transtheoretical model in the domain of physical exercise, emphasizing the significance of quantitative research. Through the widespread use of questionnaire surveys, encompassing a diverse sample of participants, a total of 659 questionnaires related to physical exercise behavior were collected from Gen Y in Chengdu, China. Detailed analysis and statistical processing of this data allow the research to present more accurate and objective conclusions, thereby further substantiating the practical application of the transtheoretical model across diverse fields. Focusing on Gen Y in China, the research explores the relationships among Stages of Change, Decisional Balance, Self-Leadership, and Self-Efficacy. The utilization of quantitative research assists in clearly capturing and quantifying the exercise behavior and attitudes of the Y generation, providing robust support for the development of relevant policies and intervention measures. In summary, this research underscores the pivotal role of quantitative research in exploring the transtheoretical model. Through extensive questionnaire surveys and data analysis, the study provides a reliable foundation for theoretical applications, analyzing the relationships among Stages of Change, Decisional Balance, Self-Leadership, and Self-Efficacy. This contributes to a more comprehensive understanding and quantification of physical exercise behavior and the characteristics of the Chinese Gen Y, ultimately enhancing the credibility and practicality of the research.