Objective: To explore the effects of group cognitive therapy on negative emotions and impulsivity among college students with Internet addiction. Methods: 33 college students with Internet addiction from one university in Guiyang were randomly divided into intervention group (n=16) and control group (n=17). Before and after the intervention, the Young s Internet Addiction Test, Self-rating Depression Scale,Self-rating Anxiety Scale and UPPSP Impulsive Behavior Scale were administered. In addition, the event-related potential (ERP) technology was used to detect the differences in EEG components related to impulse suppression between the two groups before and after the intervention. Results: There were no statistically significant changes in the scores of Internet addiction, anxiety, depression, and impulsivity in the control group before and after(P>0.05); the N1 amplitude in the control group was higher than that in the previous test(t=-3.32, -3.19, P<0.05), and the changes in the amplitude of N2 and P3 were not statistically significant(P>0.05). The depression and anxiety scores of the intervention group were significantly lower than those of the pre-test (t=2.20, 2.45, P<0.05); the negative urgency and positive urgency scores were significantly lower than those of pre-test (t=3.84, 3.44, P<0.05); the N1 amplitude of the intervention group after treatment was higher than the previous test (t=-3.08, -2.72, P<0.05), and the N2 and P3 were lower than the previous test (t=2.10, 2.07, P<0.05). Conclusion Group cognitive therapy can improve the negative emotions of college students with Internet addiction, reduce the impulsivity level of college students with Internet addiction, and improve the impulse control function of college students with Internet addiction to a certain extent.