Abstract: Ultrasonic is a special sound wave whose frequency is higher than 20 kHz. As a non-thermal physical processing technology, ultrasonic applied in microbial engineering could change the physiological characteristics of microorganisms, which in turn have different biological effects. The application of ultrasonic technology in microbial engineering mainly concentrated in the genetic breeding and genetic engineering, intensifies fermentation process, inhibition of harmful microbes, extraction of fermentation products and on-line rapid detection in the fermentation process. This paper discusses these applications progress in detail.