An electric propulsion system of electric aircraft driven by highefficiency permanent magnet synchronous motor was equipped with a vector controller. Aircrafts are vulnerable to gust encounters, which can lead aircrafts to an unstable state. The aircraft aerodynamic model during cruise under gust and the dynamic model of the electric propulsion system of the electric aircraft were established and solved, and the setting method of PI control parameters of the electric propulsion system under gust was given. We simulated the twoseater electric aircraft using MATLAB, and then carried out the experimental tests on the ground. The simulation and experimental results showed that when the aircraft encountered gust, the speed PI control parameters considering the gust conditions could effectively reduce the speed fluctuation range of the propeller.