In order to avoid the collision between the separation body and the parent body, or the occurrence of overloading and overloading of the mechanism in the separation process of wind tunnel test, a safety monitoring system is developed. The safety monitoring system adopts CompactRIO modular architecture and LabVIEW development platform, and realizes the relevant information acquisition, status display, signal processing and alarm emergency stop functions of the inter-stage separation device through sensors, data acquisition modules and upper/lower computer software. The results show that the system can detect the occurrence of overrun and collision in time and stop or power off in time, and can protect the equipment safety in the process of supersonic wind tunnel test.