In this study, we aim to investigate the therapeutic effect and safety of ALK inhibitor in ALK-positive lung cancer patients. 59 patients with ALK-positive lung cancer from August 2013 to August 2022 were retrospectively recruited. The basic information, pathological type, clinical stage and treatment strategy were collected. These patients were divided into two groups, including 29 patients of conventional adjuvant chemotherapy, and 30 cases of targeted therapy. The patients in the targeted therapy group underwent adjuvant targeted therapy with crizotinib for 2 years. The observation indicators include curative effects and adverse events. The disease-free survival (DFS) and overall survival (OS) were also analyzed. We analyzed the pathological stages after adjuvant chemotherapy and targeted therapy in lung cancer, no significant difference in the p stage N and T was found between the two therapeutic groups. However, the DFS events, DFS median time and OS median time showed significant improvement in the targeted therapy group when compared with adjuvant chemotherapy (allP< 0.05). Besides, the patients under both therapeutic regimens presented some adverse events, among them elevated aspartate transaminase/alanine aminotransferase was the most common adverse event in all the patients, followed by nausea and vomiting. Our study identified that crizotinib-based postoperative targeted therapy helps improve the prognosis of patients with ALK-positive lung cancer, confirming that postoperative targeted therapy can be considered an effective and feasible therapeutic alternative.