Objective To explore the effect of mindfulness-based stress reduction therapy on the professional identity level of psychiatric nurses.Methods A total of 80 nurses in the psychiatric department of a psychiatric hospital from April to June 2023 were selected as the study objects and they were divided into intervention group and control group according to random number table method,with 40 cases in each group.The intervention group was given mindfulness-based stress reduction therapy for 8 weeks,and the control group was given routine psychological counseling and stress relief.The scores of nursing stress scale,nurses'professional identity scale,Maslach burnout inventory-human services survey(MB1-HSS),Hamilton anxiety scale(HAMA)and Hamilton depression scale(HAMD)before and after intervention were compared between the two groups.Results After intervention,the scores of occupational identity scale in the two groups were higher than those before intervention,and the score of the intervention group was higher than that of the control group,the differences were statisti-cally significant(P<0.05).After intervention,the scores of nursing stress,HAMA,HAMD and MB1-HSS scales in both groups were lower than those before intervention,and the scores of all scales in the intervention group were lower than those in the control group,with statistical significances(P<0.05).Conclusion Mindfulness-based stress reduction therapy can reduce psychological stress and job burnout of psychiatric nurses,improve their mental health and enhance their profession-al identity.