Abstract-Temperature signal is one of the key parameters in industrial processes. Accurate and effective temperature monitoring may provide necessary device information to the operator and prevent unexpected catastrophic equipment faults due to device overheat. Compared with wired monitoring system, wireless sensor networks (WSNs) monitoring system has many advantages, such as low cost and convenient installation. This paper proposes and implements a multichannel temperature monitoring system based on WSNs module, Jennic JN5139. The hardware circuit design of the sensor node and the software design for WSNs nodes and the centralized computer using C language and Lab-VIEW respectively are given in detailed. An optimization subsection algorithm based on least square for thermocouple nonlinear calibration is also explored to increase the measurement accuracy. The prototype system is evaluated with an electric furnace temperature monitoring system. The experimental results show the feasibility and effectiveness of the proposed system.