Abstract: To obtain real-time and accurate state quantities for active safety control of the vehicle, the center-of-mass lateral eccentricity and transverse swing angular velocity are estimated based on a three-degree-of-freedom dynamics model of the vehicle and Extended Kalman Filter theory.Using the standard on-board information provided by the distributed drive electric vehicle: wheel speed, lateral acceleration, transverse swing angular velocity, front-wheel rotation angle, and other measured quantities, combined with the Extended Kalman Filter estimation algorithm to estimate the center-of-mass lateral deflection angle and eliminate the transverse swing angular velocity error in real-time, the distributed wheel side 4WD electric vehicle is developed in MATLAB environment, and a joint Simulink-CarSim simulation platform is established to select The simulation verifies the feasibility and adaptability of the extended Kalman filter in the state estimation of vehicle dynamics system.