A motor driving system has a first motor, a first motor driving control device for driving the first motor, a second motor, a second motor driving control device for driving the second motor, a controller performing communication with the first motor driving control device and the second motor driving control device, a first communication line for connecting a common terminal of the controller and the first motor driving control device; a second communication line for connecting the common terminal and the second motor driving control device, and a switch unit capable of switching each of the first and second communication lines between an enable state in which communication is possible by the communication line and an disable state in which communication is impossible under control of the controller. The controller controls the switch unit to set either the first or the second communication line to the enable state.