Abstract: A cotton field water-saving irrigation control system based on Fuzzy-PID control is designed to address the problems of low irrigation accuracy and poor operational stability of traditional cotton field water-saving irrigation systems. The system collects the real-time soil moisture of cotton fields through soil moisture sensors as the basis for control decision, combines expert experience to develop fuzzy control rules, designs a Fuzzy-PID controller, models and simulates the system in Simulink to simulate and analyse the Fuzzy-PID control method and the conventional PID control method. As shown by the simulation curves, the steady-state time of the proposed Fuzzy-PID control is reduced by about 7.3 s and the overshoot is reduced by 5.65% compared to the conventional PID controller. The test results show that the fuzzy-PID control method has better adjustment accuracy and steady-state performance, which can adjust the soil moisture in time for timely and appropriate irrigation, improve the irrigation accuracy of the system to a certain extent, and can meet the irrigation demand of cotton in large fields.