In this study, the impact of entrepreneurial college students from different backgrounds on mental health which is primarily based on the mediating role of social justice is studied. For this purpose, we have selected those start-up students who graduated from a university for one to two years as the research object, and 1890 questionnaires were distributed. The subjective family background, objective family background, social equity perception, anxiety, and depression of entrepreneurial college students were investigated, and the results were analyzed. The level of social equity and mental health of start-up college students with better birth was significantly higher than that of start-up college students with lower birth. Background, social equity, and positive emotions were significantly positively correlated, which was significantly negatively correlated with negative emotions, depression, and anxiety; Social equity played a partial mediating role in the relationship between birth and mental health indicators. Social equity helped to maintain the mental health of entrepreneurial college students from different backgrounds. This was of great significance to the entrepreneurial college students who come from a lower background.