Method and system for rolling metal blank

A method and a system for rolling metal blank are provided in the present application. The method for rolling metal blank includes: processing a metal blank to be rolled, to make a cross section of the metal blank to be rolled present a trapezoid, wherein the trapezoid has a top side and a bottom side, the top side is opposite to the bottom side, the metal blank to be rolled has a first thickness at the top side and a second thickness at the bottom side, and the second thickness is greater than the first thickness; and transmitting the metal blank to be rolled to a rolling mill, wherein the rolling mill has a upper roller and a lower roller, the upper roller is opposite to the lower roller, a gap is provided between the upper roller and the lower roller, and the top side passes through the gap for rolling.