Taking Doshan area as an example, based on the study of sequence stratigraphy, sedimentology and the lateral resolution of seismic data, this paper characterizes the Akshabulak Formation sedimentary system by using the methods of seismic sedimentology such as stratal slicing, 90° phasing conversion and frequency division. Through calibrating the attributes of strata slice to actual geological significance by combining single well facies with associated stratal slice in vertical, at least 6 periods channels are identified, in which 2 periods are in SQ8-1 Formation that indicate channels developed most widely and intensely; the channels in SQ8-2 Formation are thinning and have poor continuity;the channels in SQ8-3 Formation distribute limited and the water area is shrinking, a main transgressive process is reflected in changing shallow water and sedimentary succession in a transgressive and regressive process compared with SQ8 -1 and SQ8 -2 Formation. The result shows that the stratal slicing technique describes the plane geometry and discontinuity of the channels effectively, and it can be the geological basis for the description and prediction of lithologic stratigraphic traps in this study area.