The invention relates to a production line and production method of inequilateral channel steel for a forklift portal-frame. The production line comprises a reversing rougher and a universal finishing mill group arranged behind the reversing rougher, and the universal finishing mill group comprises a first universal finishing mill, an edging mill and a second universal finishing mill in sequence according to the arrangement order; and hole patterns with two-side flange widths being different are adopted for all rolling mills in the universal finishing mill group. The production method includes the steps that a rectangular billet is rolled by the reversing rougher and becomes an asymmetrical rolled piece required by the finishing mill group; the roughly rolled piece enters the universal finishing mill group and is rolled by the first universal finishing mill, the edging mill and the second universal finishing mill in sequence, and finally the inequilateral channel steel for the forklift portal-frame is obtained. By means of the inequilateral channel steel for the forklift portal-frame produced through the method, on the premise of guaranteeing use performance, the light weight of a forklift portal-frame system can be achieved, the material cost of the forklift portal-frame is reduced, forklift energy consumption is lowered, and safe stability of the forklift is improved.