A method and a device for synchronously controlling multiple printing presses or multiple units in a printing press can reduce power consumption and improve durability of motors and motor bearings. A synchronous control device for multiple printing presses includes machine shafts (11, 111) of a main printing press (A) and a sub printing press (B) respectively provided with drive motors (15, 115), and is configured to synchronously control rotation of the sub printing press (B) with respect to rotation of the main printing press (A). Here, drive motor brakes (16, 116) are attached to the respective drive motors (15, 115), and drive control devices (19, 20) respectively configured to release synchronous control of the drive motor (15) of the sub printing press (B) by a stop instruction and to start the drive motor brakes (16, 116) of both of the printing presses (A, B) are provided.