The invention belongs to the field of tumor biological products, and particularly relates to an chimeric antigen receptor, a gene of the chimeric antigen receptor, the recombinant expression vector ofthe chimeric antigen receptor, a CD22-CD19 double-targeting T cell and application of the T cell. The chimeric antigen receptor is CD22ScFv-L-CD19ScFv-CD8-CD137-CD3zeta and comprises CD22ScFv, connecting peptide L, CD19ScFv, a hinge region and a transmembrane region of CD8, an intracellular signal structural domain of CD137 and an intracellular signal structural domain of the CD3zeta which are connected in series. According to the chimeric antigen receptor, the gene of the chimeric antigen receptor, the recombinant expression vector of the chimeric antigen receptor, the CD22-CD19 double-targeting T cell and the application of the T cell, when B-cell line hematological malignant tumors are treated, the T cell modified by the chimeric antigen receptor not only can specifically recognize a tumor cell which is only expressed by a single target spot of a CD19 antigen or a CD22 antigen, but also can recognize tumor cells co-expressed by the two target spots of the CD19 antigen and the CD22antigen, compared with the single target spot CAR T, the double target spots CAR T have stronger anti-tumor activity, so that the immune escape of the tumor cells expressed by the low-abundance antigen is avoided, and therefore the recurrence risk is reduced.