A zigzagging control method for a workpiece in a rolling mill of four-high or more, the rolling mill including a plurality of rolls that include at least a pair of work rolls and at least a pair of backup rolls supporting the work rolls, an upper roll assembly including an upper work roll and an upper backup roll, a lower roll assembly including a lower work roll and a lower backup roll, the zigzagging control method comprising: an estimation step of acquiring at least any one of an inter-roll thrust force estimated based on an inter-roll cross angle and an inter-roll friction coefficient that are acquired through measurement or estimation and a material-roll thrust force estimated based on a material-roll cross angle and a material-roll friction coefficient that are acquired through measurement or estimation, the estimation step being performed before rolling of a tail portion of the workpiece; and a tail control step of measuring work-side and drive-side rolling loads of at least any one of the upper and lower roll assemblies, correcting rolling-load-difference information based on any two of acquired parameters including a roll-axis-direction thrust counterforce at the measurement of the rolling loads, the inter-roll thrust force, and the material-roll thrust force that act on a roll other than the backup roll, the rolling-load-difference information being calculated based on the measured work-side and drive-side rolling loads, and performing reduction leveling control on the rolling mill based on the corrected rolling-load-difference information, the tail control step being performed during the rolling of the tail portion of the workpiece. the rolling mill including a plurality of rolls that include at least a pair of work rolls and at least a pair of backup rolls supporting the work rolls, an upper roll assembly including an upper work roll and an upper backup roll, a lower roll assembly including a lower work roll and a lower backup roll, the zigzagging control method comprising: an estimation step of acquiring at least any one of an inter-roll thrust force estimated based on an inter-roll cross angle and an inter-roll friction coefficient that are acquired through measurement or estimation and a material-roll thrust force estimated based on a material-roll cross angle and a material-roll friction coefficient that are acquired through measurement or estimation, the estimation step being performed before rolling of a tail portion of the workpiece; and a tail control step of measuring work-side and drive-side rolling loads of at least any one of the upper and lower roll assemblies, correcting rolling-load-difference information based on any two of acquired parameters including a roll-axis-direction thrust counterforce at the measurement of the rolling loads, the inter-roll thrust force, and the material-roll thrust force that act on a roll other than the backup roll, the rolling-load-difference information being calculated based on the measured work-side and drive-side rolling loads, and performing reduction leveling control on the rolling mill based on the corrected rolling-load-difference information, the tail control step being performed during the rolling of the tail portion of the workpiece. an estimation step of acquiring at least any one of an inter-roll thrust force estimated based on an inter-roll cross angle and an inter-roll friction coefficient that are acquired through measurement or estimation and a material-roll thrust force estimated based on a material-roll cross angle and a material-roll friction coefficient that are acquired through measurement or estimation, the estimation step being performed before rolling of a tail portion of the workpiece; and a tail control step of measuring work-side and drive-side rolling loads of at least any one of the upper and lower roll assemblies, correcting rolling-load-difference information based on any two of acquired parameters including a roll-axis-direction thrust counterforce at the measurement of the rolling loads, the inter-roll thrust force, and the material-roll thrust force that act on a roll other than the backup roll, the rolling-load-difference information being calculated based on the measured work-side and drive-side rolling loads, and performing reduction leveling control on the rolling mill based on the corrected rolling-load-difference information, the tail control step being performed during the rolling of the tail portion of the workpiece.