A NI inversion method of linear rock physical properties transformation was introduced in previous studies,which can be used to predict gas saturation on the basis of prestack seismic data.The problem as to how to make the sensitivity analysis of the inversion results in order to correctly predict commercial gas reservoirs was discussed.By increasing the rock physical properties transform precision and strengthening the constraint of pore fluid transformation the authors further improved the inversion algorithm,which raises the accuracy of inversion effectively.The practical application results show that the quadratic equation NI inversion method can effectively predict the gas saturation in complex area.