Abstract: Organic fertilizer returning to the field is an effective means to treat livestock wastes and protect black soil. It is an urgent need to promote the green development of agriculture. Therefore,organic fertilizer spreaders are widely used as the main agricultural machinery for returning organic fertilizer to the field. In order to adjust the action speed of the fertilizer pushing mechanism of the organic fertilizer spreader and control the amount of organic fertilizer,this paper adopts pulse width modulation（ PWM） and proportional flow solenoid valve to design an electronically controlled hydraulic flow adjustment device. The solenoid valve adjusts the flow of hydraulic oil in the hydraulic cylinder pipeline,controls the advance and recovery speed of the hydraulic cylinder,so as to achieve the purpose of adjusting the amount of organic fertilizer.