An oral rehabilitation device for rehabilitating the oral cavity of a user includes a device body, a first activating member, an upper-jaw member, a lower-jaw member, and a processing unit. The first activating member is disposed on an end of the device body. The upper-jaw member and the lower-jaw member are connected to the same end of the device body and are for contacting an upper jaw and lower jaw of the user, respectively. The processing unit is coupled to the first activating member and is used to control the first activating member to drive one of the upper-jaw member and the lower jaw member to open or close relative to the other of the upper-jaw member and the lower-jaw member, such that the upper jaw and the lower jaw can be rehabilitated. The present invention further discloses a medical treatment system to which the oral rehabilitation device is linked.