Purpose <p>Breast cancer has become a stressful event that endangers the physical and mental health of women and their families. Post-traumatic growth refers to the positive psychological changes individuals experience as a result of coping with breast cancer. It can help individuals alleviate negative emotions, reduce physical and psychological stress, and increase self-confidence. The purpose of this study is to explore the influencing factors in the post-traumatic growth journey of couples where one partner has breast cancer and to provide reference information for the clinical development of dyadic interventions for couples.</p> Methods <p>Using phenomenological research, semi-structured interviews were conducted with 13 pairs of breast cancer patients and their spouses through a purposive sampling method, and the Colaizzi 7-step analysis approach was used to analyze the transcribed materials.</p> Results <p>A total of three themes and nine subthemes were distilled. The most significant facilitators of post-traumatic growth included multiple support systems, psychological adjustment in social interaction, and personal strength enhancement. Additional adaptive regulatory factors for post-traumatic growth included reconstruction of healthy behaviors and selective avoidance of negative information. The key obstacle factors of post-traumatic growth included multiple pressure challenges, family and social alienation, insufficient health literacy related to cancer, and distressing chemotherapy-related symptoms.</p> Conclusions <p>The post-traumatic growth of breast cancer patients and their spouses is dynamically interacted with and influenced by facilitator factors, obstacle factors, and adaptive regulatory factors. Medical staff can formulate dyadic intervention strategies for the post-traumatic growth of couples based on influencing factors, aiming to improve the physical and mental health of both.</p>