A wind turbine generator improved simulator including wind shear and tower shadow effect was proposed. Based on 3phase backtoback converter platform, the control system was established on the mathematical models of the directdriven permanent magnet wind power generator, it contained wind shear and tower shadow effect. In order to simplify the equation of the speed ratio and torque, a curve fitting method based on Kalman filter was proposed. It built the virtual platform in MATLAB/Simulink, which simulates the output of current, voltage and power as the load was changed. With the effect and without the effect, the mechanical torque output was simulated respectively. The simulation results showed that the platform could simulate the operation characteristics of wind turbine generator.