Abstract: Objective To explore the characteristics, relationship and risk factors of internet addiction and non-suicidal self-injury （NSSI） behaviors among college students of different ethnic groups in Lanzhou City, so as to provide references for promoting the mental health of college students. Methods A total of 6 373 college students in Lanzhou area were selected. The NSSI behavior assessment questionnaire and the internet addiction scale were used. Multiple linear regression models were used to analyze the characteristics and relationship of internet addiction and NSSI behaviors among college students of different ethnic groups. Results There were differences in gender, grade, family residence, father’s education level, whether from a single-parent family, guardian, parent-child relationship, family economic status, academic performance, degree of internet addiction, depression （patient health questionnaire, PHQ） and generalized anxiety disorder （GAD） between college students with and without NSSI behaviors （all P <0.001）. The multiple linear regression model showed that internet addiction was positively correlated with NSSI behavior scores （β = 0.497, P < 0.001）. Conclusion Male students, freshmen, students with depressive and anxious emotions, and those with internet addiction behaviors are more likely to engage in NSSI behaviors.