The differentiation therapy of breast cancer stem cells (CSCs) represents a significant strategy to treat cancer, but inefficient delivery to CSCs hinders the efficacy of differentiation agents. In this work, we report a type of functional dendrisomes constructed by the synthesized amphiphilic dendrimers, which enhance cellular uptake by breast CSCs, differentiate breast CSCs by carrying all-trans retinoic acid (ATRA), and increase the anticancer efficacy by carrying ATRA and docetaxel (DTX) in vitro and in breast cancer-bearing mice. The study further reveals the mechanism of cellular uptake by breast CSCs and uncovers the differentiation mechanism by analyzing relevant signal molecules, transcription factors, and cell cycle-associated signaling pathways during differentiation therapy in breast CSCs. Hence, this study offers a novel type of functional dendrisomes for differentiation therapy of breast CSCs and has significant clinical implications.