Abstract:Metformin is currently the first-line drug for type 2 diabetes mellitus，and has been used as an oral therapy for patients with type 2 diabetes mellitus for more than 50 years. In recent years，with the deepening of research on metformin at home and abroad， metformin has shown great potential in anti-tumor therapy. Studies have found that metformin can not only inhibit tumor growth alone， but also significantly assist in improving the efficacy of tumor radiotherapy，chemotherapy and biotherapy. There is no consensus on the specific mechanism of the anti-tumor effect of metformin，despite a large number of research results suggest that metformin can inhibit the growth of tumor cells by regulating various signaling pathways. This article discusses the signaling pathways related to the inhibition of tumor cell growth by metformin in recent years，aiming to provide new insights for clinical tumor treatment.