The present invention discloses a novel switchable dual chimeric antigen receptor-T (sdCAR-T) cell and a construction method and use thereof, which fall within the field of cellular immunotherapy for tumors. The dual chimeric antigen receptor consists of a first chimeric antigen receptor for MSLN and a second chimeric antigen receptor for FITC. A dual-targeted functional T cells regulated by specific exogenous bifunctional molecules is constructed, and the exogenous molecules are used to preliminarily discuss the in vivo and in vitro activity of the dual chimeric antigen receptor-T cell. By means of in vitro and in vivo tests, it is confirmed that the activation mode of the constructed CAR-T cell is controlled by the combination of endogenous tumor antigens and exogenous bifunctional molecules, and this combined regulation mode can significantly improve the safe application of CAR-T cell immunotherapy.