Chimeric antigen receptor T-cell (CAR-T) offers a revolutionary solution to the treatment of cancer. It has demonstrated particularly high efficacy in some cancer treatments, such as haematological malignancies. However, this method still faces significant challenges. In the treatment of solid tumor, it may lead to off-target toxicity, accelerated T-cell exhaustion, and cytokine storms resulting from excessive T-cell activity. Facing the dense stroma of the tumour microenvironment(TME), the introduction of lysosomal CAR-T cells expressing PH20 or CAR-T cells targeting fibroblast activation protein breaks down the external structure of the tumour, facilitating the entry of other CAR-T cells into the tumour to carry out killing. Knocking out the MCT-1 and A2AR genes can enhance the resistance of CAR-T cells to the TME. This approach inhibits the inflow of lactate and adenosine, thereby maintaining CAR-T cell viability. Employing multi-gene knockout or base editing techniques to modify the PD-1 gene weakens the immunosuppressive effects of the TME on CAR-T cells. Overexpressing some genes in the T cells, such as c-JUN, can enhance cellular activity, enabling the cells to survive long-term within the TME and sustain their cytotoxic effects. To prevent off-target effects and uncontrolled activation of CAR-T cells, synthetic Notch circuits have been engineered. This system is a dual-antigen recognition system and can help CAR-T cell better recognise tumor cells. This article reviews the research progress in CAR-T cell therapy, methods to enhance therapeutic efficacy, and offers a perspective on future research directions.