Abstract： Breast cancer is currently one of the most common malignancies in women. Ancient and modern traditional Chinese medicine（TCM）practitioners classify it under categories such as breast rock and breast stone，in TCM. Based on the collateral-unblocking theory，this study proposes that collateral damage and toxin accumulation and phlegm-stasis transforming into cancer constitute the core pathogenesis. The disease progression is divided into three pathological stages. 1） Early stage： Characterized by liver collateral constraint and stagnation， and phlegm-qi congealing in collaterals， mediating breast cancer onset. Treatment focuses on soothing the liver to resolve constraint and resolving phlegm to move qi to unblock collaterals，using modified Chaihu Shugan Powder combined with Er Chen Decoction. 2）Middle stage：Marked by interbinding of phlegm and stasis and toxin formation in stagnant collaterals， accelerating breast cancer progression. Treatment emphasizes eliminating stasis and resolving phlegm， and resolving toxins to dissipate masses to unblock collaterals，using modified Taohong Siwu Decoction combined with Haizao Yuhu Decoction. 3）Late stage：Defined by deficient collaterals accumulating toxins and cancer toxins damaging collaterals， affecting breast cancer prognosis. Treatment adopts reinforcing healthy qi to suppress tumors， and integrating unblocking with tonification to nourish collaterals， using modified self-formulated Fuzheng Yiliu Prescription. The therapeutic approach prioritizes unblocking as the functional principle and integrating unblocking with tonification， providing a novel perspective for TCM-based breast cancer treatment.