Adoptive cell therapy is the process of regulating patients ' own immune system through the administration of tumor-reactive immune cells to achieve the goal of eliminating tumor cells. CAR-T cell is genetically modified T cell and the CAR-T cell therapy is a kind of adoptive T-cell therapy. Compared with generally adoptive cell therapy for tumors CAR-T cell therapy offers the advantages of higher specificity and stronger cytotoxicity on tumor cells and prolonged curative efficacy. In the treatment of hematological malignancies CAR - T cell therapy proves effective. An increasing number of preclinical studies and corresponding clinical studies have been carried out to extend CAR - T cell therapy to the treatment of some solid tumors such as metastatic melanoma non-small cell lung cancer breast cancer and colorectal cancer. However it has not achieved good curative efficacy. Owing to the differences in properties between solid solid tumors and hematological malignancies CAR-T cell therapy is challenged for the treatment of the solid tumors such as on - target off - tumor toxicity immune escape caused by tumor antigen heterogeneity CAR- T cell exhaustion due to the immunosuppressive tumor microenvironment resulting in the limited therapeutic efficacy and immune toxicity. To improve the clinical efficacy and safety of CAR-T cell therapy in the treatment of the solid tumors many different strategies are developing currently based on the unique characteristics of solid tumors such as overexpressing chemokine receptors and cytokines dual CAR-T cells improving T cell metabolism adjusting the affinity of CAR. To provide a reference for future CAR-T cell therapy for solid tumors the development of CAR-T cells current challenges and associated optimization strategies for CAR-T cells in solid tumor treatment are reviewed in this paper.