Abstract：Facing the difficulties that the full 3D migration by double squire root (DSR) oneway wave equation has large computational effort,strong coherent noise produced by narrow azimuth 3D seismic data with low folds,affecting imaging effects when using this method for seismic imaging practice,the paper,combining with the crossline common offset migration theory,firstly deduced the common azimuth prestack depth migration formula based on propagation operator in double domain,then,presented a new method of common azimuth prestack migration that carries out recursive wavefield continuation along the direction of twoway vertical travel time by coordinate tranformation. It has been proved the effectiveness of the imaging method of common azimuth prestack migration in depth and time domains with the aid of migration test of synthetic data of SEG/EAGE salt dome model. Comparing with the commonused Kirchhoff prestack migration,the method showed distinctive advantages in imaging precision and resolution when processing same practical seismic data.
