Against the shortcomings of roll shape curve being complication for CVC rolling mill, a set of economic-type mill modification scheme to replace CVC rolling mill with new type OWBC HCW rolling mill was put forward. By means of axial moving of work roll, hydraulic bending-roll and roll shape optimisation, the modified rolling mill could easily control sheet shape, uniform the contact pressure between rolls and reduce the roll consume since elimination the harmful contact zone of work roll and backing roll, which are greater than rolling plate width. The scheme has the advantages of low modification cost and short modification cycle, and very adapts to the rolling mill type modification of medium and small-sized cold-rolling enterprises.