Although Minzu universities provide a platform for communication for college students from all ethnic groups, the multi-ethnic communication pattern could influence students’ well-being. To improve the well-being of these minority college students, this study analyzed the impact of intergroup contact on subjective well-being, as well as the moderating role of social support. Through a cross-sectional investigation, 860 valid data were collected from the Ningxia Hui Autonomous Region. The results found that the quantity of intergroup contact, the quality of intergroup contact, and the global intergroup contact could positively predict the subjective well-being of students at Minzu universities. Social support had a positive moderating effect. That is, the stronger the social support, the stronger prediction it had on subjective well-being from the quantity of intergroup contact, the quality of intergroup contact, and the global intergroup contact among college students at Minzu universities. Therefore, based on the methods of increasing contact opportunities, improving contact quality, and enhancing social support, Minzu universities can increase the interaction among students from all ethnic groups and so, further improve the subjective well-being of college students.