Massive multiplayer online games have become popular among Chinese university students, leading to a growing problem of gaming addiction among them. Therefore, this study develops a mobile application based on cognitive behavioral therapy (CBT) to help players improve their gaming behavior. In this study, a quantitative questionnaire was made to find out the emotional differences among different players, combined with CBT and existing research on gaming addiction. A mobile application named Have a Better Life was designed and developed based on the survey results. The experiment results were used in a qualitative way to evaluate the effect of the application on the refinement of MMOGs behavior among addicted Chinese university students. The application included seven stages of intervention covering emotion management, time planning, and social skills training. The experimental results showed that the application enhanced the players self-awareness of addictive behaviors and guided players to reduce gaming time through emotional regulation and behavior. Players develop healthy behavioral patterns and mental resilience, improve stress coping, social skills, and time management. The application offers an innovative intervention for addressing MMOG addiction through a combination of CBT and gamified design. The study provides new ideas for the application of the integration of psychotherapy and technology, proposes a special design for the cultural characteristics of different regions, and has a great significance in the health management of digital products for improving addictive behavior.