An ultrasonic surgical instrument with a detachable cannula component, comprising a cannula component and an instrument body , wherein the instrument body comprises a scalpel bar for producing an ultrasonic cutting effect; and the cannula component is mounted on the instrument body or dismounted from the instrument body by a detachable structure along the longitudinal axis of the scalpel bar; and the detachable structure comprises multiple first detachable elements; and the instrument body is fixedly connected with the cannula component by at least one of the first detachable elements; wherein the first detachable structure comprises a first boss , a first limiting slot , a stopper and an elastic element , wherein the first boss is located on the cannula component , and the first limiting slot and the stopper and the elastic element are located on the instrument body ; or wherein the first boss is located on the instrument body , and the first limiting slot and the stopper and the elastic element are located on the cannula component ; and wherein: the first limiting slot comprises a first slot parallel to a longitudinal axis of the scalpel bar and a second slot circumferential to the longitudinal axis of the scalpel bar ; the first boss is capable of sliding along the direction of the longitudinal axis of the scalpel bar in the first slot of the first limiting slot , and also is capable of sliding rotationally about the longitudinal axis of the scalpel bar in the second slot of the first limiting slot ; the stopper is configured to be capable of sliding along the direction of the longitudinal axis of the scalpel bar in the first slot of the first limiting slot , while incapable of entering the second slot of the first limiting slot ; and wherein: the stopper is connected with the elastic element , and the elastic element is capable of providing an elastic force along the direction of the first slot of the first limiting slot , and the stopper is located at an intersected point of a first slot structure and a second slot structure of the first limiting slot in an initial state under the action of an elastic force of the elastic element . the first limiting slot comprises a first slot parallel to a longitudinal axis of the scalpel bar and a second slot circumferential to the longitudinal axis of the scalpel bar ; the first boss is capable of sliding along the direction of the longitudinal axis of the scalpel bar in the first slot of the first limiting slot , and also is capable of sliding rotationally about the longitudinal axis of the scalpel bar in the second slot of the first limiting slot ; the stopper is configured to be capable of sliding along the direction of the longitudinal axis of the scalpel bar in the first slot of the first limiting slot , while incapable of entering the second slot of the first limiting slot ; and wherein: the stopper is connected with the elastic element , and the elastic element is capable of providing an elastic force along the direction of the first slot of the first limiting slot , and the stopper is located at an intersected point of a first slot structure and a second slot structure of the first limiting slot in an initial state under the action of an elastic force of the elastic element . <EOS>