A vehicle-mounted motion simulation platform based on active suspension and a control method thereof is provided. The vehicle-mounted motion simulation platform includes a vehicle body, a motion simulation platform fixedly connected to the vehicle body, an upper computer for posture control, a gyroscope, a plurality of wheels, and suspension servo actuating cylinders and displacement sensors corresponding to the wheels respectively, an electronic control unit, and a servo controller group. The electronic control unit calculates posture control parameters based on the posture instructions of the motion simulation platform input by the upper computer for posture control and posture information of the motion simulation platform measured by the gyroscope, and then outputs the posture control parameters to the servo controller group. The servo controller group controls extension of the respective suspension servo actuating cylinders according to the posture control parameters to realize follow-up control over the posture of the motion simulation platform.