This study detect with ultrasonic wave and for to walk electronic compass vehicle study by oneself main fact, mainly develop intelligent cleaning the robot. The ultrasonic system is detected and made up with 4 groups of ultrasonic wave , and examine by three form chip person who control , 18F452 of Microchip ,, dynamical system control about ship for two DC motor, also done the speed to control by the same form chip, the electronic compass uses ADCM 1100 moulds of groups, the detecting device is contacted with RS232 interface and computer. In utilize ultrasonic wave it finds range to be and only materials that tickle of interdicting etc. at the motor in the article originally, can calculate and come from and go the car position and map materials which needs clear Sao area , and utilize the map materials to do the car route rule walk to draw, match the electronic compass and revise the error, and reach the effective area and cruise.