Abstract: After the seismic data acquisition and unified processing through different years,the post-stack seismic data reflected unbalanced energy,low resolution and signal-to-noise ratio,which cannot meet the needs of exploration and research.To solve these problems,3D seismic data need to be processed step by step.In the first step,the gain compensation should be calculated both from vertical and horizontal directions,so as to solve the energy difference of the deep shallow layer and the energy mutation of the splice respectively.Secondly,the mixed phase wave deconvolution technique is used to improve the resolution of the seismic data.At last,based on the first two steps,the dip constraint median filtering processing is used to improve the SNR.After the threestep processing,the original seismic data quality has been greatly improved,which can provide reliable basic data for the subsequent construction interpretation and reservoir prediction.