With the innovative development of histone deacetylase inhibitors（HDACi），a class of drugs targeting epigenetic regulation mechanism，the treatment landscape for breast cancer patients is gradually changing. Both hormone receptor-positive and human epidermal growth factor receptor 2-negative breast cancer patients，as well as triple-negative breast cancer（TNBC）patients，can benefit significantly from combination therapy with HDACi. This article summarizes the research progress of HDACi in various molecular subtypes of breast cancer，with a particular focus on the treatment status in the Chinese population and exploration of rational combination therapy strategies in the future.