Optical Coherence Tomography (OCT) has the characteristics of fast imaging speed and high resolution. It is widely used in the diagnosis of ophthalmic disease. In order to quickly obtain the depth information of the designated surgical area in ophthalmic surgery, this paper proposes a method of applying OCT to ophthalmic surgery navigation. Based on the swept-frequency OCT system, and the real-time observation is performed by a dichroic mirror combined with a CCD camera, and the coordinates of the scanning coordinate system and the camera coordinate system are matched. The scan positioning of the OCT is completed. For the error of image reconstruction and actual coordinates caused by the self-refraction of the sample, the OCT image reconstruction error correction is based on Fermat′s principle and Snell′s law, and the mapping relationship between the OCT image and the actual structure of the sample is theoretically derived. Experimental results indicate that the OCT image of a specific location can be acquired with a low error, and the OCT image information can be corrected accordingly. The system is capable of measuring accurate information on the location of the sample.