The invention discloses an OCTS technology-based pancreatic cancer and malignant mesothelioma CAR-T therapy vector. The vector comprises lentivirus framework plasmid, a human EF1alpha promoter (SEQ ID NO. 14), an OCTS chimeric receptor structural domain and a PDL1 single-chain antibody; the OCTS chimeric receptor structural domain comprises CD8 leader chimeric receptor signal peptide (SEQ ID NO. 15), a PDL1 single-chain antibody light chain VL (SEQ ID NO. 16), a PDL1 single-chain antibody heavy chain VH (SEQ ID NO. 17), an MESOTHELIN single-chain antibody light chain VL (SEQ ID NO. 18), an MESOTHELIN single-chain antibody heavy chain VH (SEQ ID NO. 19), an antibody inner linker Inner-Linker (SEQ ID NO. 20), a single-chain antibody inter-linker Inter-Linker (SEQ ID NO. 21), a CD8 Hinge chimeric receptor linker (SEQ ID NO. 22), a CD8Transmembrane chimeric receptor transmembrane domain (SEQ ID NO. 23), a TCR chimeric receptor T-cell activation domain (SEQ ID NO. 26), and a chimeric receptor inducible co-stimulater area. In addition, the invention also discloses a construction method of the vector as well as application of the vector to preparation of medicines for treating pancreatic cancer and malignant mesothelioma.