The heating temperature is automatically adjustable; the safety device is provided; the excitation circuit board structure; the ultrasonic output frequency can be finely adjusted according to different working conditions; the ultrasonic frequency sweeping line; the ultrasonic generator has a frequency sweeping function, and the ultrasonic frequency is passed during the cleaning process. Reciprocating sweeping within a reasonable range drives the cleaning liquid to form a fine reflow, so that the workpiece dirt is quickly taken away from the workpiece surface while being ultrasonically peeled off, thereby improving the cleaning efficiency.