The present invention provides a method for identifying an inter-roll cross angle in a rolling mill of four-high or more including at least a pair of work rolls and a pair of backup rolls by, when rolling is not performed, applying a roll bending force to apply a load between rolls of an upper roll assembly including the work roll on the upper side and between rolls of a lower roll assembly including the work roll on the lower side, in a state where a roll gap between the work rolls is put into an open state, detecting vertical roll loads that act in the vertical direction on the rolling support positions on the working side and the driving side of at least one of the backup roll on the upper side or the backup roll on the lower side, and calculating a load difference between the vertical roll loads on the working side and the driving side.