The invention discloses an ultrasonic atomization device used for suspension liquid. The ultrasonic atomization device comprises a transducer shell, a transducer, an atomization tool head, a liquid spraying ring, an air inlet hole, an air outlet hole, a liquid inlet and liquid outlet holes. The transducer shell wraps the transducer. The transducer is connected with an ultrasonic power supply through a wire interface located on the top of the transducer shell. The atomization tool head is connected with the transducer. The transducer is connected with the liquid spraying ring in a clamping and buckling mode. The air outlet hole is formed in the bottom of the transducer shell. A gap between the transducer shell and the transducer is filled with heat conducting glue. The air inlet hole is formed in the upper portion of the transducer shell. Compressed air enters the interior of the transducer shell through the air inlet hole, and flows rapidly in the transducer shell cavity. According to the ultrasonic atomization device, the atomization ability and atomization efficiency of the ultrasonic atomization device are improved, the atomization of the suspension liquid and a solution is achieved, in addition, the device is not limited by liquid storage and the liquid level and can work continuously, and the ultrasonic atomization device has wide application prospects in the field of thermal power plant flue gas desulfurization and denitration systems.