The invention discloses a longitudinal speed estimation method for distributed four-wheel drive electric vehicle dynamics control. The method comprises the following steps: S10, a vehicle reference speed rough estimation module estimating free scroll wheel speeds according to the motor revolving speed and the wheel speed; converting the four free scroll wheel speeds into the speed at the vehicle mass center by using the yawing angular velocity and the signal of the steering wheel turning angle; calculating vehicle reference speed rough value by using the speed at the vehicle mass center; S20, a body deceleration rough value estimation module estimating body deceleration rough value by using the motor torque, the brake pressure, the motor revolving speed or the wheel speed, the yawing angular velocity and the signal of the steering wheel turning angle; and S30, a Kalman filter module performing filtering on the reference speed rough value and the body deceleration rough value calculated in the steps S10 and S20 by using a steady-state Kalman filter, and performing estimation and outputting the reference speed and the body deceleration. The longitudinal speed estimation method for distributed four-wheel drive electric vehicle dynamics control has higher instantaneity and accuracy.