In order to provide a special spreader for cow bedding materials, a cow bedding material hammer spreader was designed. Taking sand as the research object, an operating theoretical model of the hammer spreading mechanism was established. The gyration radius of the hammer, spreading speed, spreading angle of the material, number and size of hammer were designed and calculated. The simulation model of sand spreading was established by EDEM, and the key factors such as spreading speed, tangent angle of spreading, opening angle of upper baffle, and length of upper baffle were simulated and analyzed. The influence of each factor on spreading width, average thickness of materials accumulated on the ground, and spreading uniformity was analyzed. The simulation results showed that by increasing the spreading speed and the opening angle of the upper baffle, reducing the tangent angle of spreading and the length of upper baffle, the spreading width and spreading uniformity of the sand accumulated on the ground can be improved, and the average thickness of sand accumulated on the ground can be reduced. Under the condition that the spreading speed was 1200r/min, the spreading tangent angle was 35°, the opening angle of the upper baffle was 70°, the length of the upper baffle was 180mm, and the driving speed was 4km/h, simulations and tests were carried out. Simulation results were in good agreement with experimental data, and the reliability of the simulation analysis was confirmed. The effective spreading width was 5.1m, and the average thickness was 22mm, and the coefficient of variation of the uniformity of spreading was 31.96%, the requirement of farms was met.