Abstract: Introduction of spectrum in the appliance of the structural prototype observed data process is studied in the paper, three different methods are adopted in solving the facing problems in order to extract the regular part called supplementary item from the residue series, which is got by modeling. Supplementary model is obtained by attaching the supplementary item to the original model, this model has been attested by the real project to have the ability to promote the improvement of predicting precision and the exactitude in evaluating the structural behavior.