Ultrasonic cleaning device and ultrasonic cleaning method for underwater structure objects

The invention discloses an ultrasonic cleaning device and an ultrasonic cleaning method for underwater structure objects. The cleaning device comprises a power supply portion and a cleaning portion. The cleaning portion comprises a cleaning part and a waterproof device used for preventing the cleaning part from water. The cleaning part comprises an ultrasonic cleaning device and a water jet cleaning device. The ultrasonic cleaning device comprises an ultrasonic electric energy generation device and an ultrasonic transduction device which are connected. A water jet generation device comprises a high pressure water pump and a sprayer which are connected through a water jet pipeline. The cleaning method is that ultrasonic wave generated by the ultrasonic cleaning device is focused through an amplitude variation rod in the ultrasonic transduction device and damages insoluble dirt, low pressure high speed water jet formed by the high pressure water pump and the water jet pipeline in the water jet cleaning device i