Starting from the approximation of Zeoppritz equation presented by Mr.Shuey, the paper obtained more accurate zero-offset reflectivity by fitting reflectivity changed with incident angles, which improved the signal-to-noise ratio of seismic data,while did not fundamentally change the relationship of reflected amplitudes changing with offsets in original CMP gathers of seismic data that can further inverse the accurate section of AVO attributes.The results of theoretical models and practical seismic data showed that in comparison with former-adopted AVO inversion the method not only can reflect the relationship of amplitudes changing with offsets at offsets, but also has no limitation of incident angles.