Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is challenging to treat and lacks targeted therapeutic drugs in the clinic. Natural active ingredients provide promising opportunities for discovering and developing targeted therapies for TNBC. This study investigated the effects of daurisoline on TNBC and elucidated its potential mechanisms. Using network pharmacology, a correlation was identified between daurisoline, derived from Menispermum dauricum, and breast cancer, particularly involving the Notch signaling pathway. The effects of daurisoline on the proliferation, migration, and apoptosis of MDA-MB-231 and MDA-MB-468 cells were evaluated in vitro. Additionally, the impact of daurisoline on the growth of MDA-MB-231 xenograft tumors in nude mice was assessed through in vivo experiments. Expression levels of Notch signaling pathway-related proteins, including Notch-1, NICD, PSEN-1, Bax, and Bcl-2, were examined using molecular docking and Western blotting to explore the underlying mechanisms of daurisoline’s anti-breast cancer effects. It was revealed that daurisoline could effectively inhibit the proliferation and migration of MDA-MB-231 and MDA-MB-468 cells and promote apoptosis. Furthermore, it significantly reduced the growth of subcutaneous tumors in nude mice. Notably, daurisoline could reduce the hydrolytic activity of γ-secretase by binding to the catalytic core PSEN-1, thereby inhibiting activation of the γ-secretase/Notch axis and contributing to its anti-TNBC effects.This study supported the development of naturally targeted drugs for TNBC and provided insights into the research on dibenzylisoquinoline alkaloids, such as daurisoline.