A type of direct nozzle injection sprayer was developed. By comparing with traditional spraying machines, the detailed structure and advantage of direct nozzle injection sprayer, especially to the injection unit, were analyzed. In order to dose pesticide precisely, a type of fast reaction valve based on electromagnetic principle was designed. The structure and control strategy were discussed in detail. The test of sprayer performance was carried out. The results showed that there existed a polynomial relationship between the water injection and the water pressure, and an exponential relationship between the pesticide injection and the opening time of PWM signal. The determination coefficients of both models were above 0.9. Besides, the uniformity of the six injection units within one boom section was tested and showed good performance.