Based on collecting meteorological data and field test result, accurate irrigation and automatic control fertilization using the technology of artificial intelligence are compiled by language C, which according to water equilibrium principle, object yield of crop and information of fertility character and so on. The chip micro-comupter is the center of system controller. The high precision detector of soil moisture monitors, devices of soil moisture, irrigators and fertilizing tanks connect with the controller. So the intact control system is built. It can do many things, such as, gathering data, necessary rate of irrigation and fertilizer application to various crops in the period of growth, flow control of spray irrigation, accomplish irrigation and fertilization automatically by way of manmachine conversation and menu choice. According to different crop, different regions, climate and crop of different periods, the system can judge whether the amount of water stored of farmland and soil drops to the lower limit index that the crop and confirm quantity of irrigation and fertilization. In the end, irrigating and fertilizing can be finished automatically. The system can based on the width of field auto-adjust sprinkler pattern range and divide several microplot by the plot-area;it can adjust praying density and discharge of fertilizer based on compatibility of the fertilizer and allocating fertilizer which the system running. So automatic accurate irrigation and fertilization is realized. The system can offer seven corp decision-making actualize project of the accurate irrigation and fertilization such as the wheat, the corn, the cotton, et al. It has the favorable expansibility.