A single channel detection method of sulfur hexafluoride (SF6) concentration without reference channel presented based on acoustic attenuation in air in this paper. This method uses the theoretical sound pressure value of sound waves through the detection channel in air as a reference, and measures actually the attenuated sound pressure value through the detection channel. The ratio of the two sound pressure values as a function of SF6 concentrations derived to calculate the SF6 concentration. A wireless sensor node is designed using Zigbee wireless SOC of CC2430 based on acoustic attenuation method. Experiments and simulation demonstrates that when SF6 is rare, the linear relationship between SF6 concentration and the ratio of the two sound pressures does exist. The effectiveness of the single channel SF6 concentration wireless sensor and the wireless sensor node has verified.