Abstract: In this paper, the intelligent control system of integrated water and fertilizer machine is the research object.By analyzing the water and fertilizer demand in the process of crop growth, an intelligent control system of integrated water and fertilizer machine is built by using industrial computer as the upper computer and STM32 control board as the lower computer.The system can determine the irrigation amount and fertilizer amount according to the crop growth state, irrigation area and environmental parameters, combined with the crop growth demand, and carry out the distribution and transformation of irrigation and fertilizer application time according to the fertilizer dissolution characteristics, and finally carry out the corresponding fertilizer discharge and irrigation operation under the output command of STM32 control board.Through the test, the results show that the system can better regulate the dynamic fertilization process, and effectively reduce the delay time of the system.