This article introduces a method of extracting the typical defect vector of strip shape. In the method, firstly the strip shape defects are primarily classified, then the unit typical strip shape vector is extracted according to similarity among strip stresses, and finally the typical ratio coefficient is solved with the k-means cluster approach. Aiming at the unit typical strip shape vector extrac-ted, a taper work roll was designed and put into a large-scale trial. It is shown that the shape quality of rolled strips is better than before. The comprehensive flatness is below 5 IU, and side and middle composite buckles are basically eliminated.