Medical ultrasonic knife, medical ultrasonic knife system and robot-assisted ultrasonic knife system

The invention provides a medical ultrasonic knife, a medical ultrasonic knife system and a robot-assisted ultrasonic knife system, and belongs to the technical field of medical instruments. The medical ultrasonic knife comprises a liquid flow sleeve and a knife rod, the liquid flow sleeve comprises a sleeve body and a first protruding part, the sleeve body is provided with a mounting cavity penetrating through the two opposite ends of the sleeve body, and the first protruding part is located on the inner side wall of the sleeve body. The cutter bar penetrates through the mounting cavity and is in pivot joint with the liquid flow sleeve, the cutter bar and the liquid flow sleeve can move in the extending direction X, and a second protruding part is arranged on the outer side wall of the cutter bar. The first protruding part and the second protruding part are matched so that when the liquid flow sleeve rotates in the first rotating direction, the first protruding part and the second protruding part can be stagg