Abstract: The wide-line seismic survey has been used successfully and widely in onshore petroleum exploration because of the low cost and good effect.However,offshore wide-line seismic survey application cases have not been reported in China.In order to compare the effects of offshore wide-line data acquired with different configuration,a sail line with 2 sources and 3 streamers was selected from a 3D seismic survey in Baibu Gulf Basin,South China Sea.Combined with the CDP definition,imaging testing has been conducted systematically with 2D/3D Pre-stack Depth Migration (PSDM) on the chosen data.In addition,comparison analysis has been finished about imaging results and S/N ratio.The testing results show that the 2D Kirchhoff PSDM algorithm can achieve better results than 3D Kirchhoff PSDM algorithm in imaging processing of offshore wide-line seismic data.Compared with vintage 2D Prestack time migration data,the application results with 2D PSDM data by regional wide-line survey in the study area are better.