Objective To identify the latent classes of dyadic coping among breast cancer patients undergoing postoperative chemotherapy and their spouses, and to examine the influencing factors, so as to provide references for developing targeted nursing interventions. Methods A total of 206 dyads of breast cancer patients undergoing postoperative chemotherapy and their spouses were recruited through convenience sampling, then they were investigated by using a general information questionnaire, the Chinese version of Dyadic Coping Inventory, the Chinese Perceived Stress Scale, and the 10-item Kessler Psychological Distress Scale. Latent profile analysis was used to identify latent classes of dyadic coping, and multinomial logistic regression was conducted to explore the associated factors. Results Four latent classes of dyadic coping were identified among the participants:collaborative coping group (22.33%), spouse-dominated group (40.29%), patient more active group (16.99%), and overall deficient coping group (20.39%). Influencing factors included patients′ employment status, monthly household income, perceived stress and psychological distress in both patients and their spouses (all P<0.05). Conclusion Dyadic coping among breast cancer patients undergoing postoperative chemotherapy and their spouses exhibits significant group heterogeneity and distinct interaction pattern characteristics. Nurses should implement couple-based, classification-specific precise interventions based on the characteristics and influencing factors of the dyadic coping,so as to enhance dyadic coping and improve psychosocial health for both partners.