The invention relates to the technical field of hot continuous rough rolling, in particular to a rolling mill unit deviation rectification control method and device. The rolling mill unit deviation rectification control method comprises the steps that for a first rolling mill unit comprising a first vertical rolling mill and a first horizontal rolling mill, in the process of reciprocating rolling of band steel through the first rolling mill unit, at an odd rolling pass, according to the change of rolling force deviation of the first horizontal rolling mill, a first levelling compensation value is obtained, a roll gap of the first horizontal rolling mill is adjusted, a first deviation rectification compensation value is obtained, the center line of the first vertical rolling mill is adjusted, according to the change of the rolling force deviation of the first vertical rolling mill, a second levelling compensation value is obtained, and the roll gap of the first horizontal rolling mill is adjusted; during an even rolling pass, according to the change of the rolling force deviation of the first horizontal rolling mill, a third levelling compensation value is obtained, and the roll gap of the first horizontal rolling mill is adjusted. By the adoption of the rolling mill unit deviation rectification control method and device, crossing stereoscopic deviation is conducted on the band steel in the longitudinal direction and the transverse direction, and the deviation rectification accuracy is improved.