A tandem press line switches from a synchronized high-speed press control to a synchronized low-speed press control when a high-speed, line master control signal is switched to a low-speed line master control signal. For a press having a slide position which has been determined to be within a press region, the synchronized low-speed press control can be switched to a non-synchronized high-speed press control that is based on a non-synchronized high-speed individual press control signal that is not synchronized with the low-speed line master control signal at least during a period in which the slide position is within the press region, and the non-synchronized high-speed press control can be switched to the synchronized low-speed press control on condition that a press resynchronization point has been reached.