The invention discloses a practical conversion method for a proportion-integration-differentiation (PID) correction link in a generator excitation system model, and belongs to the technical field of power system modeling. According to the conversion method, the generator excitation system model defined by PSD-BPA, fast analysis of stability using the extended equal area criterion and simulation technologies (FASTEST) or power system analysis software package (PSASP) software can be converted into a corresponding excitation model defined by the IEEE Std 421.5-2005 standard. Compared with other methods, the amplitude-frequency characteristic of an original excitation system model can be accurately simulated under the premise that the model self-definition function of target software does not need to be grasped; the complicated process of building a self-defined model in the target software is avoided; and the model conversion efficiency is effectively improved on the basis of ensuring the credibility of data conversion and simulation analysis results.