Abstract: Based on the problem of foreign body sensation caused by contact with the larynx in clinical use of round tube laryngoscopes at home and abroad, an ergonomic D-type mechanical structure was proposed without affecting imaging, and a medical rigid D-type endoscope for laryngeal examination was designed and manufactured. The relative aperture of the objective lens was improved by the designed endoscope system, and a matching relay system was designed, with a full field of view angle of 60° and a viewing angle of 90°, and the relay system adopted a double telecentric structure with a working length of 170 mm. The image square resolution of the endoscope system is 94 lp/mm, and the MTF is greater than 0.2. When the object distance is 10 mm, the object square resolution is 52.58 lp/mm, and the object square angular resolution is 11.45 c/(°). Experimental tests show that the designed endoscope can provide clear imaging under the condition of reducing the contact area with the larynx, which meets the expected indicators and actual use needs.