The invention discloses a water washing robot sighting system based on ultrasonic distance measurement and image identification and a method thereof. The system comprises a network camera and an online ultrasonic distance measurer; an industrial control computer receives signals acquired by the network camera and the online ultrasonic distance measurer; the online ultrasonic distance measurer marks observing equipment with a red light spot from above; the position of the red light spot is a water washing position; the network camera acquires scene images; a color identifying algorithm is used for automatically identifying the red spot to obtain coordinate information of the red spot in an image space so as to determine a water gun hitting position; the obtained water gun hitting position information is returned to a robot controller to control the robot movement; and the water gun hitting position is controlled to be the appointed position. The visual guide control of an electrified water washing system is realized through a machine visual related algorithm, so that the robot autonomation degree is effectively improved, and a greater effect on the improvement of the robot washing efficiency is achieved.