The invention provides a method of knocking out an NRK cell Slc22a2 gene by utilizing CRISPR-CAS9. According to an Slc22a2 gene sequence, a gRNA expression vector based on a CRISPER-Cas9 system is constructed, is taken as an Slc22a2 gene targeting vector and is transported into an NRK cell to obtain an Slc22a2 gene knocked-out NRK cell. The Slc22a2 gene knocked-out NRK cell can be used as an ideal cell model to simulate deletion of OCT2 protein in a human kidney environment and is used for studying application of the OCT2 protein in the aspect of transportation of drugs, toxins and other small molecule substances.