Abstract: The DEA model is widely used to evaluate the relative efficiency as a kind of objective decision method with multiple indexes,but the two basic models,the C²R model and the C²GS² model,which are frequently used at present,meet limitations while they are used alone,the evaluation results are often unsatisfactory.In order to solve this problem,a mixed DEA model has been built in this paper,and it is used to evaluate the validity of the business efficiency of listed companies.At the same time,the paper explains how to use this mixed DEA model,and has verified the feasibility and rationality of the model.

Key words: comparative efficiency, decision making units, effective ness appraisal, mixed DEA model, principal component analysis