Abstract: There exists some severe but normal problem that the crop fertilization is uneven such as over or too less fertilized and the concentration can’t be well controlled.As to the situation, this paper presents a spherical mixing precision fertilization system, which can realize automatic irrigation, fertilization, injecting fertilizer and mixed fertilizer.The paper introduces the device structure, automatic control system, the software structure and module of the upper computer and the characteristics and the control algorithm of mixed fertilizer system.The electric conductivity(EC) and pH value can be accurately controlled and real-timely regulated to meet the various needs different crops.Utilizing embedded technology, frequency conversion technology, automatic control technology and computer information technology developed the automatic control system of the irrigation and fertilization.The experimental result proves that this system has a good quality for EC and pH valve adjustment, steady performance and good practicability.And the system is stable, reliable and easy to operate, which will greatly enhance the coupling effect of water and fertilizer and fertilizer efficiency and improve the yield and quality.