The invention discloses an overturn foot supporting device, and belongs to the technical field of auxiliary mechanisms additionally arranged on seats. The overturn foot supporting device comprises a driving device, an overturn device and a pedal device; the driving device is provided with a driving motor, a transmission rod, a movable toothed plate, a fixed toothed plate, an eccentric shaft and a connecting plate; the overturn device is provided with a pair of hinge mechanisms and a connecting rod and can be unfolded, folded and bent; and a user can step on the pedal device conveniently. The overturn foot supporting device has the advantages that the overturn foot supporting device is small in size, simple in structure, convenient to assemble, good in action flexibility, high in precision and firm in locking; hinges are used for transmission, and various parts are machined and manufactured conveniently, so that production cost is low; and the overturn foot supporting device can be connected with an optional seat with relative space, and is simple in connection and wide in application range.