Abstract: In order to meet the needs of variable spray technology for boom sprayers, a variable spray control and test bench for boom sprayers were designed to realize real-time control and performance testing of existing variable spray devices. The variable spray control and test bench are composed of a control system and a data acquisition system. The control system is based on Siemens S7-200 series PLC, which is composed of a power system, drive system, flow system, and variable control system. The data acquisition system uses data acquisition modules and sensors to obtain pipeline flow, pressure, torque, driving speed and other parameters. Real-time display and storage of the collected parameters can be achieved through LabVIEW software. The flow accuracy test under the speed condition shows that the average flow error is 4.0%, which can be used as a technical reference for judging the performance of the variable spray device. The test shows that the test bench can effectively control the variable spray control components of the boom sprayer in real-time to meet the requirements of the boom sprayer. The performance test requirements of variable spray control components of sprayers provide technical reference for the formulation of technical specifications for variable spray quality evaluation.