This study was conducted to design new instruments to solve the current issues of one-hand control and the obscuring of the endoscope by blood during transnasal endoscopic surgery. An endoscope holder and an electronically controlled irrigation-suction system were designed and manufactured. The feasibility and effectiveness of the designed instruments and operation models were verified in a model transnasal endoscopic surgery procedure performed on a mongrel dog. During the operation, one hand was used to perform the operation and move the endoscope, and the other hand was used for irrigation and suction to keep the surgical field and the endoscope clear. The combined use of an endoscope holder and an electronically controlled irrigation-suction system facilitates single-surgeon bimanual transnasal endoscopic surgery in a model surgical procedure. The clinical value of this technique warrants further research.