Abstract: Based on the data of university students' consumption, spatio-temporal correlation between students is defined. We designs an algorithm to detect spatio-temporal association, and the social relations network is constructed by using the spatiotemporal relation detected, and the social network is optimized, and social network relationship between students is found out. The social network relationship is verified by judging whether the students are in the same class. Experiments show that this method can accurately extract the social network relationship of students.