To provide a rough universal rolling method for a flanged shape steel represented by a wide flange shape steel, and a channel steel, etc., at a high pressure-drop rate and stably.

In order to prevent a web buckling failure, the rough universal rolling method to roll an in-process shape steel workpiece having a flange using shaped blooms as material and a rough universal rolling mill consisting of a pair of upper and lower horizontal rolls and another pair of right and left vertical rolls provides a rolling process of rolled material over its full length by setting the roll gaps formed by a pair of the horizontal rolls and a pair of the vertical rolls or by setting the relative position of a plane including the axis of the pair of the vertical rolls against a plane including the axis of the pair of the horizontal rolls or by setting both together so that the plate thickness pressure drop provided to a rolled plate by the rough universal roll mill is satisfied with the projection length rate in the individual input flange pressure drop against the input web thickness and with the proper area under the plate thickness pressure drop beforehand.