Abstract: In order to reduce the construction time as far as possible in a blast furnace construction process,because the blast furnace main body space is narrow and small,many upper air overlapping operations should be done,which causes the construction to be more complex.Therefore,to guarantee the blast furnace system's construction safety,the method of the fuzzy mathematics and AHP method are used for a quantitative expression of general safety state of a construction.The computation is not only simple,but the operational is strong and easy to grasp by managers in the construction site to discover the potential safety problems as early as possible.As compared with other theoretic methods,it is suitable to the managers at worksite.Through the example of analysis,it has proven that the method is reasonable.