Abstract: Tumor necrosis factor-α(TNF-α) is an inflammatory factor mainly produced by mononuclear macrophages in the body, which can directly kill tumor cells and has almost no toxic effect on normal cells at physiological doses. TNF-α plays an important role in various stages of tumor development, such as tumor cell proliferation, invasion, metastasis and apoptosis, through a variety of mechanisms. The factor not only promotes the apoptosis of tumor cell, but also promotes the growth and invasion of tumor cells. In this paper, the signaling pathways related to TNF-α in malignant tumors and its dual roles in malignant tumors and application in tumor treatment were elaborated. These findings may provide new ideas for the clinical development of anti-cancer drugs related to TNF-α.