Abstract: The interaction between rivers and tides is an important part of studying the sedimentary process of estuaries. However, the existing research only considers the frequency and intensity of tides and ignores the salinity factor, and the research on the influence of salinity is still very limited. In this paper, the influence of salinity on the deposition process of estuaries and the distribution of sand bars is studied by sedimentary numerical simulation technology. First, establish an ideal estuary model based on the characteristics of modern estuaries; then, establish 8 ideal scenarios covering typical estuary conditions, and compare 4 sets of salinity factors; finally, analyze, count and compare the simulation results, to establish the proportional relationship between the length, width and thickness of the sand bar. The results show that salinity speeds up the diffusion of sand and mud, making the sedimentation phenomenon of salinity estuaries more obvious. The absence of salinity shows the irregularity of the sedimentary morphology of the estuary, and the salinity models all show the symmetry of the distribution of estuary sand bars. The sand bars in the outer estuary are more obviously distributed along the provenance, and the sand bars are long. The aspect ratio and length-to-thickness ratio are larger than those of the model without salinity. The study of salinity factors will improve the accuracy of estuarine sedimentation simulation, can provide accurate templates for estuary sedimentation models, and also provide theoretical guidance for the exploration of estuarine oil-bearing reservoirs.