In order to improve quality of consistency test, a new relational model named double weighted gray relational was proposed. The first structure was main frame of the new model, in which the process of system was divided into many phases by its practical characteristics in work, and then different phases were weighted by its contribution to the whole system. The second weight was to improve the accuracy of model. Its weight was fixed by the distance of reference data and test data. By doing this, the new model was in view of the similarity by subtraction and the nearness by division between the simulation and flight-test time series, so it had higher accuracy and reliability. Finally, two case studies were given to show reasonability and validity of the improved model.