As a special method to evaluate relative efficiency, DEA has many advantages in evaluating efficiency of steel industry of China But there are the disadvantages in traditional DEA method That is the input and output indexes are all decided by the evaluators, which makes the persuasion of the evaluation results become decrease at the beginning In order to solve such disadvantages and make the evaluation of steel industry more precise and impersonality, this paper combines traditional DEA with AHP, taking the 21 list companies of steel industry in China as evaluation targets Firstly, AHP is used to set up evaluation indexes system Then DEA is used to compute the general efficiency, technological efficiency and scale efficiency At the end, the paper puts forward some suggestions to improve the efficiency of the companies that are not DEA effective