The invention discloses an ultrasonic wave stirrer which comprises a shell, a stirring barrel and an ultrasonic wave generation mechanism, wherein ultrasonic wave vibrators are arranged in the ultrasonic wave generation mechanism; the ultrasonic wave generation mechanism can be used for transmitting ultrasonic waves into the stirring barrel and can be also used as a clamping mechanism for the stirring barrel; the ultrasonic wave stirrer is also provided with a stirring device with expansion devices; the stirring device is used for enabling a stirring wheel in a rotating state to do up-and-down reciprocating motion in the stirring barrel to uniformly mix raw materials. According to the ultrasonic wave stirrer, extracts and a solution are fully combined; the ultrasonic wave generation mechanism capable of doing expansion motion can be used for transmitting the ultrasonic waves to the stirring barrels with different sizes, so that the types of equipment are reduced and the cost is lowered; the stirring barrel can be fixed and locked; in an extracting process, the ultrasonic wave generation mechanism can be used for avoiding the phenomenon that ultrasonic wave extraction is affected by vibration of the stirring barrel, so that extraction is complete, and the efficiency is improved; the ultrasonic waves act on the periphery of the stirring barrel, so that the extracts are high in combining speed, and the mixing effect is enhanced.