This paper takes shell-and-tube heat exchanger as the research object, designed and built an ultrasonic descaling experimental device, and carried out an experimental study on the principle of ultrasonic descaling in the frequency range of 11–21 kHz. The effect of ultrasonic descaling was initially verified through experiments, and the rule of influence of changes in the size of the heat transfer tube and the installation position of the heat transfer tube on the descaling effect was mastered, and the influence of changes in acoustic power, frequency and other parameters on the descaling effect was deeply analyzed. In addition, the relationship between the ultrasonic descaling effect and the vibration amount of the heat transfer tube was also explored. This study can provide some guidance for the industrial application of ultrasonic scaling technology.