Abstract: The permanent magnet generator system has a complex structure and a large number of nodes. In the real-time electromagnetic transient simulation, if the traditional modeling method is used, the calculation of the system admittance matrix will be too complicated, resulting in a serious limitation of the simulation scale. Therefore, this paper proposes a fixed-admittance modeling method of permanent magnet synchronous generator (PMSG) based on virtual impedance compensation. This method is based on the traditional generator model, and the generator admittance matrix is fixed by compensating the virtual impedance on the rotor. The impedance parameters are optimized with the goal of minimizing the transient error. By combining the constant admittance model of voltage source converter, a complete constant admittance model of PMSG can be established and electromagnetic transient simulation can be performed, thus saving a lot of computing resources. Simulation experiments show that the model has high simulation accuracy, and can be used in discrete hardware simulation platforms such as FPGA, with good applicability.