A gait rehabilitation machine and a method of using the same for lower-limb rehabilitation. The gait rehabilitation machine includes: a frame; a rear supporting member provided at the frame so that the back side of a human body can lean against the rear supporting member; a thigh supporting member corresponding to a thigh of the human body and pivotally connected to the frame; a shank supporting member corresponding to the corresponding shank of the human body, pivotally connected to the thigh supporting member, and having a pedal to be stepped on by the human body; a knee supporting member corresponding to the corresponding knee of the human body and provided at the thigh supporting member or the shank supporting member; and a transmission device for driving the shank supporting member to move. Thus, a patient can do lower-limb gait rehabilitation exercise without using a suspension system.