Abstract: For the converter's high-rise frame of the large main furnace building,its structural system is very complex.So it's very difficult to reinforce it.Combined a steel mill building,it was researched its loading,structure model,the reason of crack,reinforcement feasibility.With the determination of the bracing frame's relative strength index,the reasonable structure model was provided to reduce the reinforcement quantity.It was also research the maximum value of nominal stress under loading and welding,regular production was assured according to appropriate unloading.According to different calculation results and current conditions,different reinforcement design methods for the high-rise frame were introduced.The reinforcement results were very good.Which provided a useful reference for other similar projects.