The mental health problem of “left-behind generation” college students is an important part and work content of college personnel training. In this study, college students in a university in Henan Province were taken as the research object. SCL-90 symptom self-assessment table was used to investigate the mental health status and problem characteristics of “left-behind generation” college students. It was found that 18.57% of college students had positive symptoms, among which 4.2% were students with moderate and severe mental problems. The mental health level of students without left-behind experience is better than that of students with left-behind experience, and there are significant differences in each factor score. Students with left-behind experience are more likely to have interpersonal sensitivity, terror, paranoia, psychotic body and other problems. The positive symptoms of students without left-behind experience accounted for 16.75%, and the positive symptoms of students with left-behind experience accounted for 23.95%. The mental health level of girls is better than that of boys. Finally, from the perspective of ecosystem, using the theory of “ecological restoration”, the author tries to solve the mental health problems of “left-behind generation” college students from the level of individual psychological repair and interpersonal environment repair. First, at the individual level, we should strengthen selfawareness and psychological self-help consciousness, and establish a life attitude of self-reliance; The second is the interpersonal environment level, from the family to repair the family internal relations, rebuild the family support system level, from the school to improve the mental health education system, and gather strength to help the “left-behind generation” college students solve problems.