Abstract: Traditional stratal slicing method often adopts proportional interpolation, which tends to cause diachroneity. An innovative sedimentary bottom shape description method for palaeogeomorphology research was proposed in X Sag, East China Sea. The application of seismic Wheeler domain transformation enables the precise construction of a chronostratigraphic framework. The "void" seismic facies of Wheeler domain can reveal reservoir boundary information. Strict control of the bottom shape and reference plane can better improve the quality of stratal slice by combing seismic Wheeler domain transformation with sedimentary bottom shape description method. On this basis, by integrating coupled paleogeomorphic slicing for sand control analysis, the application effectiveness of stratal slices is further improved. This technical method has been successfully applied in A gasfield in East China Sea, where it accurately characterized the sedimentary bottom shape of P3 tuff layer. Wheeler domain stratigraphic slicing was completed by adjusting the sequence framework based on the bottom shape and reference plane, yielding two phases of stratal slices with well-defined geological characteristics. Favorable results have been obtained in depicting the planar distribution of sand bodies and the characteristics of sedimentary evolution, providing strong support for well deployment.