Mental health is of great significance in college students, but how to effectively evaluate and intervene in college students' mental health is still a challenge. The aim of this study is to explore a method based on branch and bound algorithm to assist college students in mental health assessment and intervention decision-making. Firstly, we introduce the basic principle and application background of branch and bound algorithm. Then, we describe in detail the steps and processes of applying branch and bound algorithm in the study of college students' mental health. We also use the data of the empirical study to demonstrate the application effect of branch and bound algorithm in the mental health assessment of college students. Finally, we discuss the limitations of branch and bound algorithm in the study of college students' mental health, and propose the direction of future research.