The invention relates to the technical field of hot rolling and particularly relates to a control method and system for the plate type of a hot-rolled plate. The control method comprises the following steps that roll bending values are set into a group of values with periodic changes in the control system for the plate type of the hot-rolled plate, and a control model of the hot-rolled plate determines a group of roll stringing values with changes according to the roll bending values; the roll bending values and the roll stringing values are used as control data of the control system for the plate type of the hot-rolled plate to realize control on the plate type of the hot-rolled plate. The system comprises a data setting unit, a data determination unit and a control unit. The control method and the system for the plate type of the hot-rolled plate provided by the invention have the advantages that the step-length adjusting amplitude in roll stringing is larger, and the problem that the local part of the hot-rolled plate is protruded due to small step-length adjusting amplitude in roll stringing is solved.