The invention discloses an electromagnetic multi-disc clutch device, a water pump with the electromagnetic multi-disc clutch device, and a transportation means, which can solve the problem that temperature increase of engines is influenced due to the fact that the common vehicle-mounted water pumps enter a working state while the engines starts. The electromagnetic multi-disc clutch device can select the suitable start time according to different temperature conditions in running of the engine. The clutch device includes a drive unit, a driven unit, an operation unit, and an iron core; the drive unit includes a support, a belt pulley, and a drive friction plate; the driven unit includes a driven shaft and a driven friction plate; the operation unit includes an attraction disc, an elastic portion, an operation block, and an inclined slide block; the attraction disc is pressed on the support through the elastic portion, the support transmits power to the driven friction plate, and the driven friction plate drives the driven shaft to rotate; and after the iron core is energized, the iron core drives the attraction disc to keep away from the support, and the drive friction plate is separated from the driven friction plate.