Aiming at the problems of the low efficiency of manual pesticide application in the greenhouse, the narrow operating space of plant protection machinery, and the possibility of poisoning the pesticide applicators due to the closed space, a high-pressure atomization spraying equipment for the greenhouse was designed. The spraying equipment adopts two-way communication between PLC and HMI to realize the adjustment of atomization pressure and atomization flow, and the control equipment completes automatic spraying. To determine the best working parameters of the spraying equipment, orthogonal tests were conducted with atomization pressure and atomization nozzle aperture as the test factors and the coefficient of variation of the fog volume distribution as the evaluation index. The optimum combination after parameter optimization was determined to be as follows: atomization pressure of 4 MPa, atomization nozzle aperture of 0.4 mm. The test results under the optimal parameters showed that the spray distribution coefficient of variation was 10.5%, and the uniformity of fog volume distribution was good to meet the requirements of spraying in greenhouses.