According to the situation that a small high-speed wind tunnel at a low level of informatization and the flow field of the wind tunnel needs to be manually adjusted to achieve stability.Based on the flow field control process, this paper designs a LabWindows/CVI-based upper computer control system and applies it in a small high-speed wind tunnel. The system communication uses the OPC communication protocol based on DataSocket, The upper computer can efficiently and reliably realize the information interaction with PLC by receiving the data of Ni OPC server;the upper computer software uses multi-threading, asynchronous timer and other technologies to realize the functions of real-time data display, historical data record and storage, and friendly human-machine interface which is convenient for operators to use.Through a lot of test and analysis, the newly designed flow field control system has fast response, stable operation and high accuracy, which meets the design requirements of high-speed wind tunnel control system. It has certain reference value for reducing energy consumption, improving information technology and automation level of wind tunnel.