The present invention relates to a four-wheel independent steering system with a steering motor mounted on a double wishbone suspension knuckle. The four-wheel independent steering system comprises the steering motor, an upper swing arm, a lower swing arm, and a knuckle for driving wheels to steer. The upper swing arm and the lower swing arm are connected with a body. The steering system also comprises a motor bracket. The motor bracket is connected with the knuckle by a thrust bearing, the steering motor is fixed on the motor bracket, and the output shaft of the steering motor is connected with the knuckle by a key, the upper swing arm is connected with the motor bracket through a hooke joint, and the lower swing arm is connected with the knuckle through a spherical hinge. Compared with the prior art, the advantages of the double wishbone independent suspension and a wire steering system are combined, good suspension kinematic characteristics are achieved, a steering servo motor assembly is arranged on the wheel rim, so that the integration of the suspension and the steering system is realized, and the integration level is high.