Abstract:3D P-R splitting migration is recommended here,which is a new 3D wave equation single-step migration using finite difference,Its es-sential is that the continuation of 3D migration wave equation is per-formed twice in}(or ζ)direction using a half step respectively,In the former half-step case,the second partial derivative with respect to x is taken in implicit scheme while the second partial derivative with re-spect to y is taken in explicit scheme.In the latter half-step case,forsymmetry,the second partial derivative with respect to y is written in implicit scheme while the second partial derivative with respect to xis written in exiplicit scheme.Thus,a very simple 3D difference equa-tior}can be obtained through simplification, This difference equation has two important advantages;(1)It brings higher difference accuracy and less frequency dispersion than Clearbout's splitting method does,(2)It can be partially decomposed into a series of 2D equations so that it takes easier solution and less computation than Wa Zaitianjs four -point average method does;Real processing results show that this me-thod can result in both good migration of dipping reflection events and reliable fault positions, thus greatly improving 3D migration section.