Abstract: As the main force of adaptive immunity, T cells can attack pathogen-infected cells and tumor cells, playing their roles in maintaining body homeostasis. T cell receptor (TCR) expressed on the surface of T cells can recognize the antigen peptides presented by the major histocompatibility complex (MHC), converting the antigen binding signal into intracellular tyrosine phosphorylation signal, and triggering downstream signaling pathways to activate T cells. Clinically, T cell receptor-engineered T cell (TCR-T) therapy is expected to make a breakthrough in the treatment of solid tumors. This review briefly elaborates on the signal transduction mechanism of TCR and compares the differences and similarities between TCR and chimeric antigen receptor (CAR) in order to help us better understand the working principle of TCR-T and to propose new strategies for designing better T cell therapy products, seeking to further expand its clinical application in solid tumor treatment.