Abstract: Disclosed is an sgRNA guiding a PD1 gene for cleavage to achieve the efficient integration of exogenous sequences. The method for gene editing a PD1 gene in cells includes the steps of introducing a nuclease and an sgRNA into cells, and gene-editing the PD1 gene. The sgRNA guides the nuclease to cleave the PD1 gene and forms a broken site, at which an exogenous donor repair template can also be introduced, so that CAR-T elements can be directionally inserted at the specific site of the PD1 locus to construct enhanced CD19-CART cells with PD1 knockout in one step.