Chimeric antigen receptor（CAR）- T cell therapy has changed the traditional treatment of hematological malignancies and has shown significant efficacy. However, the clinical application of CAR-T cells is limited by long production cycle, high price, and side effects such as cytokine storm, so it can not be widely used in clinical practice. Natural killer（NK）cells are an important part of the body’s innate immune response. Compared with CAR-T cells, CAR-NK cells can significantly reduce the probability of neurotoxicity, cytokine storm, and graft versus host diseases. CAR-NK cell therapy is gradually becoming a research hotspot, but there are still some urgent problems to be solved, and further optimization of the construction strategy is needed to achieve its clinical translation. This paper will review the construction strategy and the research progress in tumor immunotherapy based on the latest literatures at home and abroad, in order to provide valuable reference for application of NK cells in the treatment of malignant tumors.