By means of extension method, a new qualitative and quantitative evaluation technique is established to evaluate synthetic benefit evaluation of enterprises. The model obtains the index weight using incidence function and computes the incidence degree and adopts the optimal degree evaluation approach. A demonstration is applied to illustrate and validate advantages of the method. The result indicates that this method, simple and clear, is not only easier to be implemented on computer but also can be used to carry out risk control better. The approach is flexible and can be extended into other fields.