Abstract: In order to improve the power generation efficiency and power generation capacity of low concentration gas generating sets effectively, field measurements and records of their operation were carried out,through path analysis of the data, the correlation between gas source temperature, environment temperature, plant temperature and power generation efficiency was obtained. The influence of the water content of gas source and the temperature of gas source on power generation efficiency was calculated through theoretical analysis. The results show that the main factor affecting the power generation efficiency is the water content of gas source, followed by the temperature of gas source. In view of the key influencing factors, a dehydration system combined with residual heat cooling and mechanical is proposed, which improves the efficiency of low concentration gas generating sets by improving the quality of low concentration gas intake.