A mobility aid with rehabilitative and guiding functions includes a main body, a processing unit, a guiding module, a detection module, an inertia sensor, a recording module, and an electricity module. A rehabilitation and guiding method includes the steps of: A) constantly projecting a visible light beam to a next-step position of the mobility aid B) moving the mobility aid to its next-step position under the guidance of the visible light beam C) constantly emitting an ultrasonic wave to a next-step position of at least one of the users feet to define a detection area D) detecting whether the foot is moved into the detection area E) recording the moving process of any of the steps A through D and notifying a remote device of the moving process and F) detecting any of the steps A through D and, if an abnormal condition occurs, sending out a warning message.
