Background: Internship nursing student's mental health was typically poor during the epidemic, particularly anxiety, depression, and post-traumatic stress disorders which should be handled with assistance and intervention. This study was aimed to evaluate the effect of Dialectical behavior therapy -based intervention on the psychological impacts of Covid-19 among internship nursing students. Method: A total of 260 Internship Nursing Students (Study group) were received a dialectical behavior therapy intervention session for four weeks. This group was compared with 260 Internship Nursing Students (Control group) without (DBT) intervention sessions. Tool one A structured Interviewing Questionnaire, Tool two: Zung Self-Rating Anxiety Scale, Tool three: Zung Self-Rating Depression Scale, and Tool four: The Impact of Event Scale (IES) were used in this study. This study was carried out at the Faculty of Nursing, Menoufia University. A quasiexperimental research design two groups (Study and control group) was utilized. Results: There were no significant differences in total score of anxiety, depression, and post-traumatic stress subscales between the study and control group before the (DBT) intervention sessions while after the (DBT) intervention sessions the study group's anxiety, depression, and post-traumatic stress total scores were significantly lower than the control group. Conclusion: During the epidemic prevention and control, dialectical behavior therapy can successfully decrease the anxiety, depression, and posttraumatic stress of the Internship Nursing students. Recommendations: DBT therapy may be implemented in the future in school psychological counselling to help college students cope with unpleasant emotions. Furthermore, it can aid in the regulation of emotions and better satisfy the psychological demands of medical and nursing students as well as college psychological counselling development needs.