In this paper, a three-dimensional spiral cochlear Finite Element (FE) model was established by using PATRAN software based on the experimental data of synchronous light source imaging from Shanghai Institute of Applied Physics, Chinese Academy of Sciences. The acoustic-solid-liquid coupling analysis was carried out by NASTRAN software and the effects of fissura ante fenestra sclerosis on spiral cochlea were simulated in the paper. The satisfactory agreements between simulated results of ratio of displacement at 12 mm from Basilar Membrane (BM) to that at the vestibular window and experimental data in the literature confirm the validity of the FE model. Comparing the frequency response of the basilar membrane of normal and diseased ears, it can be found that greater hearing loss occurs at low frequency (100-600 Hz) and high frequency (2000-10000 Hz), but the hearing loss is less in the middle frequency. In this paper, the numerical simulation is used to make up for the lack of related researches and it provides a new way for clinical treatment of cochlear lesions.