The wireless sensor net based on ZigBee was introduced.The ZigBee technology was used in detection of the transmitting shaft torque.A kind of design scheme of monitoring torque system based on ZigBee technology was presented. The hardware circuit was designed with CC2430 wireless frequency chip as the main chip, including date collection module, receiving and processing module. Sensor program and serial port communication program between upper machine and lower machine were designed. Tree network with nodes was made according to ZigBee protocol, to implement monitoring and controlling for the transmitting shaft torque. Test indicates the feasibility of the monitoring system, the design purpose is reached and the system has a broad application prospect.