The sedimentary process and evolutionary model of crevasse fans are of great significance for predicting fluvial reservoirs and remaining oil potential. Taking the Dongyingzi fan in Liangcheng county as an example, based on satellite imaging and field geology, sedimentary features of Dongyingzi fan was analyzed.Using the Delft3D program, we designed the simulation gridding system, simulation parameters, and boundary conditions to establish a numerical model of the crevasse fan. The plane distribution of sedimentary thickness, flow velocity and sand content at different numerical simulation stages were analyzed, as well as vertical sedimentary structure of the crevasse fan. The sedimentary model of crevasse fans was summarized to discuss its significance for Reservoir architecture. Research suggests that the crevasse fans consists of crevasse channels, composite proximal fans, and an distal fans. From a humid to an arid climate, the formation process of crevasse fans can be divided into four stages, which are river crevasse stage, proximal-fan forming stage, proximal-fan flourishing stage and diatal fan forming stage. As the flooding hydrodynamics decreases, crevasse channels, composite proximal fans and diatal fans are formed in sequence. The composite proximal and distal fans are sand-rich area, which are favorable types of sand bodies during the exploration. Crevasse channels are mud-rich area as the main type of interlayer. Composite proximal fans around the crevasse channels is the main site for residual oil enrichment in the later stage of hydrocarbon development.