Objective:To explore effects of dyadic coping mode on marital relationship, functional exercise compliance and posttraumatic growth in breast cancer patients so as to provide a basis for nursing care of breast cancer patients.Methods:From January 2018 to December 2018, we selected 70 patients with modified radical mastectomy for breast cancer at the First Affiliated Hospital of Zhengzhou University. All patients were randomly divided into experimental group ( n=33) and control group ( n=37) . Control group carried out the routine nursing, while experimental group implemented the intervention based on the dyadic coping mode. We compared intervention effects of two groups with the Locke-Wallace Marriage Adjustment Test, Functional Exercise Compliance Scale for Postoperative Breast Cancer Patients and the Post-Traumatic Growth Inventory (PTGI) . Results:One case was lost in experimental group and 32 patients completed the study. Three cases were lost in control group and 34 patients completed the study. One month after discharge, scores of the Locke-Wallace Marriage Adjustment Test of patients in experimental group and control group were (117.36±16.44) and (108.25±15.32) respectively with a statistical difference ( t=-2.325, P<0.05) . Scores of three dimensions of Functional Exercise Compliance Scale and "Relating to Others" dimension of PTGI in experimental group were higher than those in control group with statistical differences ( P<0.05) . Conclusions:Dyadic coping mode based intervention can improve the marital relationship and functional exercise compliance of breast cancer patients. However, the effect of dyadic coping mode on posttraumatic growth will still require the large sample and long-term research.