A control system based on STM32 microcontroller was designed for the electric self-propelled maize-peanut strip compound planting pesticide application machine, in order to meet the agronomic requirements for the pesticide application of maize-peanut strip compound planting. The selection and design of key components such as the driving motor, steering mechanism, spray boom and anti-drift device, and pesticide application pipeline for the pesticide application machine were carried out. Real-time data collection is achieved using flow sensors to monitor pipeline liquid flow and speed sensors to track chassis driving speed. The incremental PID algorithm is employed to adjust the proportional control valve opening in real-time. This dynamic adjustment ensures accurate and responsive control over the pesticide application process. As a result, the system implements variable spray control. An APP control software was developed based on Android phones, achieving remote control of the pesticide applicator. The accuracy test of flow control showed that the relative error between the target flow rate of a single nozzle after regulation and the actual flow rate η≤4.0%. The variable application experiment showed that during the experiment, the average overshoot of the application system was 2.7%, and the difference between the application amount and the theoretical value was 2.1%. The fog droplet deposition test showed that the number of fog droplets deposited had a range of 4 drops/cm2, and the minimum deposition amount per unit area was 35 drops/cm2, which met the national standard.