During the treatment of non-small cell lung cancer ( NSCLC) , many patients have developed drug resistance due to the use of targeted EGFR inhibitors. The main reasons for drug resistance are EGFR site mutations and bypass activation. Activation of ALK pathway is one of the major types of bypass activation. A recent authoritative study indicates that ALK is closely related to immunotherapy. This article reviews the treatment of ALK in tumors from three aspects: the structure and physiological function of ALK, the small molecule inhibitor of ALK, the biological function of ALK and its related treatment methods for NSCLC, and prospects future directions for better application of ALK in the treatment of NSCLC.