Aimed at the whole military aircraft, the paper tries to solve the contradictory between keeping model effective and choosing the right expository variables. The basic modeling idea based on Effectiveness Indexes is analyzed and the form of models is established. According to the demand of cost modeling, the Effectiveness Indexes' constructing method is studied deeply. Finally, the cost modeling process based on Effectiveness Indexes is introduced through an example. In order to compare the effect of methods, some other models are established at the same time with the DAPCA model and PLSR. The comparison results explain that the models based on Effectiveness Indexes are better, because more parameters which impact the cost obviously are considered and the variables in the regression process are reduced, thus the models' validity is guaranteed.