Abstract: To investigate the explosion characteristics of gas in large pipes and the characteristics of gas explosion injury of the mice at the end of the pipe, the gas explosion tests were carried out with three typical concentrations in the pipe with 2 000 mm diameter, and several healthy mice were placed at the end of the pipe to observe the injury and death. Three characteristics of gas pressure, temperature and flame propagation under different volumes and concentrations were analyzed, and the damage characteristics of tissues and organs of rats after explosion injury were observed. The experimental results show that explosion shock wave and temperature are the main causes of explosion casualties. When the gas concentration is 9.5%, the volume is 1.6 m³, the explosion pressure, the explosion temperature and the flame propagation speed reach the peak value. At this time, the number of dead mice was the largest, and the degree of damage was the highest. The main injuries were burns, pulmonary hemorrhage, and brain tissue hemorrhage.