Abstract: Carnitine palmitoyltransferase 1 (CPT1) is a fatty acid β-oxidative rate-limiting enzyme of fatty acid β-oxidation (FAO) present in the outer membrane of mitochondria, which is closely related to metabolic diseases and tumors. Numerous studies have shown that various subtypes of CPT1 are abnormally expressed in cancer cells and play an important role in resistance to metabolic stress. With the development of tumor immunotherapy, its role in immune cells and organs has also attracted attention. This article aims to review the biological functions of CPT1 and the role of different subtypes in tumor metabolism and immune regulation, and the research progress of its inhibitors, providing new ideas for cancer treatment.