Endoscope with disposable cannula

The invention discloses an endoscope with a disposable cannula. The fixing base is arranged in the operation part, the water vapor catheter and the biopsy catheter are fixedly connected between the fixing base and the fixing head in parallel, the biopsy catheter and the water vapor pipe are led out of the corresponding positions of the operation part, the disposable biopsy catheter and the water vapor pipe are convenient, rapid and smooth to install and connect, and the water vapor catheter and the biopsy catheter are parallel, ordered and free of interference; the disposable insertion part sheath, the movable head, the biopsy tube and the water-gas tube are integrally formed, so that the integral replacement is convenient and fast; in use, the insertion part sheath, the movable head, the biopsy tube, the suction tube, the suction valve, the Y valve, the water gas tube and the operation part protection sleeve which are polluted are all disposable components, can be directly replaced after being used, are poll