In the three-dimension seismic data processing, displaying the post-stack seismic data of adjacent lines in the longitudinal direction may save plotting paper and reduce processing cost. The paper presents the seismic data processing method to create 3D seismic plotting data which can be displayed in the longitudinal direction. The method introduces that the drawing data set can be created by separating 3D post-stack data set, prolonging data record lengths, modifying the line number and merging 3D post-stack data set. Through real plotting, post-stack seismic sections of different lines may be displayed in the longitudinal direction. Therefore the processing method saves paper greatly and reduces processing cost.