Abstract: For hydrogen as a new form of energy, there is still a certain gap in the marketization of its application technologies such as combustion. As a kind of efficient combustion equipment, the jet burner can effectively improve the thermal utilization rate of energy. In this paper, the combustion process of hydrogen in the jet burner was simulated, the flame characteristics under different oxygen supply ratios were analyzed, and the changes in combustion temperature, flame height and morphology, and pollutant concentration under different air-fuel ratio conditions were compared. Then, the 21-step hydrogen combustion mechanism with 10 components was adopted in the simulation, and thus sensitivity analysis and finite element simulation were performed for the key components in pure hydrogen combustion. The results show that: the peak value of hydrogen combustion temperature decreases with the decreasing of oxygen supply. The flame height decreases significantly with the decreasing of the oxygen supply in case of the air-fuel ratio lower than 1, and the flame height gradually tends to be stable when the air-fuel ratio is greater than 1. Besides, the total amount of the pollutant NO_x produced increases with the increase in oxygen supply ratio, but its concentration distribution will be affected by other factors such as flame morphology. In this research, a suitable range of air-fuel ratio was proposed for the jet burner from the perspective of improving the thermal efficiency, so as to provide a reference for the combustion utilization of hydrogen energy.