A guiding device for guiding a mobile robotic vacuum cleaner to a charging base is composed of a central sensor, a left sensor, and a right sensor. The mobile robotic vacuum cleaner is composed of a main processor and a driving system. The charging base includes an optical emitter for emitting optical signals toward a predetermined direction. The central sensor, the right sensor, and the left sensor are electrically connected with the main processor and mounted to a charging sensor set zone. In this way, the main processor can judge whether the mobile robotic device correctly moves toward the charging base according to the signals detected by the sensors and then adjustably control the moving direction of the mobile robotic vacuum cleaner via the driving system to guide the mobile robotic vacuum cleaner to accurately move toward the charging base.