Abstract: According to the hose pump flow as the driving mechanism of the precise fertilizer fertilization system fertilization in pulse, the problem of the fertilizer, this paper designed the cotton membrane based on PID algorithm under fertigation closed loop control system, the system can fertilize by measuring the pipe flow, the fertilization flow back to the inverter, inverter will actually flow and users of the given fertilizing flow set point, the output PWM signal control in the hose pump motor speed, realize the closed loop control; Tencent cloud platform used in this system, the client and server, database, as the frame of remote monitoring system, touch screen will fertilization data collected through the 4 g network sent to the server, the server receives the data and sent to the database, the database is responsible for collecting, sorting and save fertilizer application data, the client will receive the application data to demonstrate to the user.The experimental results show that compared with the traditional fertilization method, the PID algorithm of fertilization closed-loop control system effectively reduces the pulse of the hose pump as the fertilization drive mechanism, improves the fertilization accuracy, meets the requirements of modern agriculture for precise fertilization, and achieves the goal of precise fertilization.