Abstract: The characteristic of supersonic oxygen jet is one of important influencing factors of metal smelting. Under the same conditions, the characteristic of supersonic oxygen jet would be affected by the oxygen preheating temperature of the inlet nozzle. In this study, the characteristic of supersonic oxygen jet under different preheating temperatures are studied by a numerical simulation method, and results are compared and analyzed with the previous literature results to show that: the velocity, temperature and pressure of supersonic oxygen jet along the axial direction have the same tendency under different preheating temperature conditions: the values firstly keep constant, then continually decay, and finally tend to environmental parameters; the velocity, temperature and pressure at the nozzle outlet are greater under the high preheating temperature compared with those under the low preheating temperature; the density of the jet becomes low with increasing preheating temperature, so that the stable section length of jet decreases.