The present invention is a rehabilitation walking boot, which includes a foot support and two leg supports. The foot support includes a top surface, a bottom surface and two lateral edges. The two lateral edges are configured with slots for insertion and fixation by the inserts of the two leg supports. The leg support insert is configured with a flexible positioning locker protruded on one side, and one side of the slots of the foot support lateral edges is configured with a locking part. The side walls of the slots are configured with perforated fixing holes. The rehabilitation walking boot can be dismantled more conveniently, and the leg support can use either combined type or fixed type linkages to the foot support.