An escape system used for a car being sunken into water and its ultrasonic component are illustrated. The ultrasonic component has a case and an ultrasonic module, and the escape system used for the car being sunken into water has the ultrasonic component and a mainboard. The present disclosure utilizes the property of the ultrasonic to recognize the type and thickness of obstacles which are accumulated in the ultrasonic component, and to determine whether a warning message for sweeping the obstacles should be sent, so as to maintain a sensitivity of the ultrasonic component and further to prevent the ultrasonic component from mistakenly judging that the car is sunken in water.