The invention provides a stratigraphic sedimentary facies dividing method. The method includes: researching the log fancies of each well in a research area of a target stratum, determining electrical characteristic parameters and lithological characteristic parameters thereof to divide sedimentary microfacies of different stratums of each well, and establishing a logging facies mode; calculating the seismic attribute of a seismic axis of the target stratum, and displaying the seismic attribute in an interpretation workstation; exporting a seismic attribute display file of the target stratum from the interpretation workstation and converting the file to a seismic attribute vector diagram; enabling coordinates of the logging facies at each well point to correspond to plane coordinates of seismic data volumes on the seismic attribute vector diagram, and giving interpretation results of the logging facies; and defining the sedimentary facies of each pattern according to the logging facies of the same coordinates and patterns of a seismic attribute graph. According to the method, the sedimentary facies of sand-shale formations can be accurately predicted, the distribution condition of sand-shale sedimentary facies belts can be simply and rapidly determined, and the exploration work of the sand-shale sedimentary formations can be better and more rapidly accomplished.