Abstract: In the process of smelting stainless steel in AOD furnace，a large amount of alloy and slag lead to a large heat gap，which affects the smooth progress of “decarburization and chromium retention”. Xingtai Iron and Steel Co.，Ltd. adopts “DEP→AOD→LF→CCM” smelting process of stainless steel，high carbon content of molten iron can produce a large amount of CO gas，at the same time phase decarburization slag with high viscosity and melting point，the granular characteristics. CO gas can be quickly released from slag，spillage will not occur in the process of converting，which provide basic conditions for CO secondary combustion. The effective utilization of heat released by CO secondary combustion can provide certain heat for the blowing process. The industrial practice shows that，with the increase of lance position，the proportion of CO secondary combustion begins to increase gradually. In this working condition，compared with two types of lance heads，  the application effect of three hole gun is the best combining compensation of heat and the influence on furnace life. the proportion of CO secondary combustion reaches 20 %，the heat compensation is  about 150 ℃，the cost is reduced by about 40 yuan/t，the economic benefit is remarkable.

Key words: AOD, CO secondary combustion, oxygen lance