Abstract: A set of pesticide dispensing agricultural UAV based on STM32 control was designed．After setting path and pesticide information, it could automatically navigate and complete operation．Cooperating with the UAV, it could eliminate pests 360 ° without dead angle, without personnel operation and save time and labor．Automatic navigation design was based on control algorithm of GPS positioning and three-axis heading angle measurement, and used SDIO bus to operate SD card．In order to record navigation operation data, real-time self-test code was added, the path could be corrected, and obstacle avoidance system wass added to ensure safety of personnel and vehicles．This system was developed based on STM32 development board, which had strong expansibility and compatibility, and new functions could be added in the future．