Water and fertilizer integration technology is a new technology in modern agriculture that integrates irrigation and fertilization． It is of great significance to improving the utilization of water and fertilizer and reducing the environmental pollution in agricultural production． This paper studies the key devices in water and fertilizer integration technology，and uses the SolidWorks three-dimensional design software to establish a three-pass bypass fertilizer-applicator fertilizer-mixed fertilizer system structure based on parallel jet pumps，and uses FloEFD to perform flow field simulation analysis and system． The performance test shows that an effective reference model for a mixed fertilizer system is established． The test results show that under the action of 2．2 kW suction pump，the system can achieve stable and uniform suction of water and single element liquid fertilizer，and the maximum error of the actual value of the three-channel absorption fertilizer and the simulation value is 2．06%． The feasibility of the structural design of the fertilizer system provides a reference for the design and optimization of the automatic fertilizer spreader．