Abstract: With the development of microbial fermentation technology, microbial fermentation is widely used in food industry. As a new physical treatment method with low energy consumption, ultrasonic technology has been widely used in food industry, especially in fermentation engineering. The appropriate application of ultrasonic technology in fermentation engineering can improve the fermentation efficiency of microorganisms. The article summarizes the application of ultrasonic technology in microbial fermentation, including the application of non-destructive fermentation monitoring and ultrasound-assisted microbial fermentation. And the mechanism of ultrasound-assisted fermentation is explored, including the various responses of microorganisms to ultrasound and the changes of metabolites caused by ultrasound in cells. These studies provide theoretical basis for the application of ultrasonic technology in the field of food fermentation.