Chimeric antigen receptor (CAR) T-cell therapy has been proven to be an effective strategy for the treatment of hematological malignancies. At present, how to prepare CAR-T cells efficiently, quickly, and safely is one of the urgent problems to be solved. The durability and activity of engineered T cells in solid tumors need to be further improved, and the strategy of T cells penetrating the tumor microenvironment also needs to be improved. In addition, although the problems mainly caused by T-cell biology are being solved, the manufacturing mode and process still need to be improved to ensure that CAR-T cell therapy can be widely used. This paper summarizes some strategies that can improve the efficacy of CAR-T cells.