At present, the chassis of the high clearance sprayer mostly adopts the traditional four-wheel steering structure. When working in the complex paddy field environment, the sprayer often gets stuck in the mud and cannot turn. A new type of chassis based on four wheel independent electric drive steering structure was designed. The chassis consisted of three main parts, the front and rear steering structure and the frame. The front and rear steering mechanism was connected to the frame by plane bearings, so that the steering mechanism can freely rotate around the fixed point on the frame. The four wheels were fixed on the front and rear steering mechanism, and the steering control purpose can be achieved by controlling the output torque of the four wheels. According to the characteristics of the structure, a modeling and control method was proposed. The two steering mechanisms were modeled separately, and part of their dynamic models were obtained. The unmodeled dynamics and external disturbances were regarded as total disturbances, and then an extended state observer (ESO) was designed to observe the total disturbances. Then the output was used to cancel out the total disturbance, and the undisturbed linear model was obtained. Then a cascade proportion controller was designed to control the steering. Finally, Matlab was used to identify and simulate system parameters and carry out physical verification. The simulation results showed that when the step signal was used to simulate the disturbance, the observed value of the disturbance can converge to the actual disturbance within 0.5s. After the disturbance observer converged, when the expected turning angle was suddenly increased from 0° to 20°, the rising time of the turning angle tracking control response curve was 1.9s, and the overshoot was 2.3%. The test results showed that when the sprayer was traveling on a flat road at speed of 1m/s, the rise time of the steering angle of the front steering mechanism was 3.1s, and the rise time of the angle of rear steering mechanism was 2.0s, which verified that the control method had a good control effect. When it was working in the field under full load, it can easily cross a muddy deep trench with width of 20cm and depth of 40cm, which verified that it had good passing ability in the field.