[Abstract] Objective To report the method of cochlear implantation in patients with severe or profound deafness with vertical segment of facial nerve covered round window. Methods The clinical data of 5 patients with severe or profound deafness with vertical segment of facial nerve covering round window admitted to Beijing Friendship Hospital of Capital Medical University from January 2015 to January 2021 were retrospectively analyzed, including medical history, audiological data, imaging data, and surgical methods. Results Of the 5 patients, 4 cases had the vertical segment of facial nerve completely covering round window, and round window could not be seen by adjusting the patient's body position and microscope angle. The cochloar implant electrode was implanted through the retrofacial approach. One case had vertical   section of facial nerve parially corering round window, round window was visibe ofter adjusting the patient's position and  anale of microscope. The posterior wall of the bony external auditory canal was ground to the level below the tympanomastoid fissure until round window was fully exposed and electrode was inserted. Electrodes were successfully implanted in all pa- tients, intraoperative neural response telemetry (NRT) was all elicited. No postoperative complications were observed, such as facial nerve palsy, collapse of posterior wall of external auditory canal and balance disorder. Conclusion For patients with severe or profound deafness, different surgical methods can be selected according to the coverage degree of round window during cochlear implantation. For patients with complete coverage, retrofacial approach can be used. For patients with partially coverage, the electrode implantation can be completed by grinding the posterior wall of the external auditory canal to lower level.