Abstract: In this paper, the parameters such as fuel consumption, oxygen consumption, cutting speed and carbon dioxide emission of modified propane, modified pentane and acetylene in the process of cutting steel plates with different thicknesses are studied experimentally, and the performance of three different welding fuels in hot cutting is compared and analyzed. The results show that the modified pentane has good thermal cutting performance under the same test conditions. Then, this paper analyzes the emission pollutants of liquid modified pentane with good thermal cutting performance after mixing with air at different vaporization temperatures. The results show that the lower the liquid temperature of modified pentane, the lower the emission value of air pollutants after combustion. The research results provide technical basis and reference for industrial production to choose low-carbon, energy-saving and environmental-friendly welding and cutting fuels.