Abstract: In order to accurately predict and evaluate the characteristics of gas hydrate deposits, quantitative study is required to be conducted by frequency attenuation gradient properties for seismic data. Influenced by random noise, it is easy to cause calculation error for the gas hydrate segments with high frequency attenuation gradients. An improved frequency attenuation properties extraction method is then proposed in this paper, which may reduce the random disturbance of the seismic spectrum slope fitting and get effective signal frequency absorption properties. The method was applied to the detection of gas hydrate in the Shenhu area in the northern South China Sea. The calculated results can accurately depict the boundary of the gas hydrate body to meet the needs in quantitative prediction of gas hydrate.