The current surgical navigation system requires the doctor’s sight to switch back and forth between the display screen and the patient, which can easily cause visual fatigue and affect the safety of the operation. In response, an optical surgical navigator based on mixed reality was introduced herein, which enabled the navigation information to be directly fused into the surgical area. The navigator was based on mixed reality (MR) glasses and a binocular vision tracker system. A novel virtual-real registration scheme was proposed, which established the mapping relationship between the virtual model coordinate system and the real world based on the tracker measurement. The wireless communication between the data processing unit and the MR glasses was realized, and the virtual model can be overlapped with the patient’s surgical area for real-time navigation. The accuracy of the optical navigator was verified with the virtual-real fusion display experiment based on a skull model sample. The results show that the dislocation error between the virtual model and the real sample is about 4.5 mm, and the display refreshing rate reaches about 15 frames per second, which can verify the feasibility of the proposed scheme and its potential for practical clinical application.