Rotary drum type operating microscope optical system

The invention discloses a rotary drum type operating microscope optical system which comprises an imaging system and a lighting system, the imaging system is composed of a large objective lens, a zoom body and an observation head which are sequentially distributed along a light path from an object plane to an image plane, and the rotary drum type operating microscope optical system is characterized in that the large objective lens is a first glued lens group formed by gluing a first lens and a second lens; the focal length range of the first glued lens group is 200-300mm, the illumination system comprises a light source, and a first light collecting lens, a light filtering device, a second light collecting lens and a reflective mirror which are sequentially distributed along a light path emitted by the light source, and an optical axis of the zoom body and an optical axis of the illumination system are respectively positioned on two sides of a central optical axis of the large objective lens; the device has t