A PDL1 block CAR-T transgenic vector for suppressing immune escape includes: AmpR sequence containing ampicillin resistance gene (SEQ ID NO: 1); prokaryotic replicon pUC Ori sequence (SEQ ID NO: 2); virus replicon SV40 Ori sequence (SEQ ID NO: 3); eWPRE enhanced posttranscriptional regulatory element of hepatitis B virus (SEQ ID NO: 11); human EF1a promoter (SEQ ID NO: 12); lentiviral packaging cis-elements for lentiviral packaging; humanized single-chain antibody fragment PDL1scFv1 (SEQ ID NO: 21), PDL1scFv2 (SEQ ID NO: 22), or PDL1scFv3 (SEQ ID NO: 23) of human PDL1; IRES ribosome binding sequence (SEQ ID NO: 25); IL6 signal peptide (SEQ ID NO: 26); human antibody Fc segment (SEQ ID NO: 27); and chimeric antigen receptors of the second or third generation CAR for integrating recognition, transmission and initiation. A preparation method of the PDL1 block CAR-T transgenic vector and an application thereof in a preparation of anti-immune escape drugs.