A walking aid device including a moving body, a message receiving element, a positioning element, and a processor is provided. The message receiving element, the positioning element, and the processor are respectively disposed at the moving body, and the message receiving element and the positioning element are respectively electrically coupled to the processor. The message receiving element is configured to receive a message from a target, and the positioning element is configured to locate a position of the moving body. When the message from a target is received by the message receiving element, the processor determines an orientation of the target according to the message, and the positioning element locates the position of the moving body. The processor produces a position data according to the orientation of the target and the position of the moving body, and controls the moving body to move to where the target is located.