Abstract-With the aim to solve college students' mental subhealth problems, this paper discriminated the related concepts such as health, mental health, mental sub-health, analyzed the causes of college students' mental sub-health from themselves, their families, the community, schools, I also constructed an intervention system of college students' mental sub-health, including mental intervention, education intervention and entertainments & sports intervention in this paper. The results indicate that college students' mental sub-health problems should be taken seriously and the scientific intervention system can help to guide to foster college students' mental health. The main innovation of this paper is to build intervention system for college students' mental sub-health.