In this paper, taking thermocouple as an example, the Design of a kind of new Low-power Wireless Sensor Node Based on The Communication Protocol of HART6.1 is presented. It builds the temperature measuring circuit of thermoelectric couple by analyzing the relationship between the output of the sensor and the input of the measurement module. It compensates the temperature in the way of measuring the inner temperature of MSP430F149, and improves the measurement precision in the process of software development. To realize the data transmission and display, wirelessly and in real time, the Protocol for the Communication between WIA wireless module and bottom data sampling unit is designed based on the Protocol framework of HART6.1. The experiment shows that this kind of wireless sensor node features the following characteristics, the stable and credible communication quality, low-power and high precision.