Abstract: Numerous wells within the Haizhong depression of the Beibuwan basin have demonstrated significant advancements in oil and gas extraction, indicating promising exploration prospects. Consequently, investigating the sedimentary evolution patterns and influential factors in this region is crucial. By examining core and well logging facies, this study analyzes the attributes of beach bar sand bodies and identifies sedimentary facies through seismic facies analysis, attribute assessment, and paleogeomorphological considerations. The findings indicate that beach bar sand bodies exhibit distinct characteristics across different facies: (1) Within core facies, these sand bodies commonly display features such as sand cross-bedding, parallel bedding, storm sedimentary sequences, and a "four-stage" pattern in probability grain size accumulation curves. In logging facies, they demonstrate continuous funnel-type logging facies with multiple reverse cycles, while seismic facies show micro-hump reflections and strong amplitude wave seismic reflections. Geographically, beach bar sand bodies tend to develop at the southwest dip end of the Weisouthwest low uplift and the western side of the southern gentle slope belt,the longitudinal upper beach bar sand bodies exhibit mutual superposition, indicating the sedimentary features of frequent migration and multi-stage superposition of beach bar sand bodies in response to fluctuations in lake levels.. (2) The positioning and distribution of beach bar sand bodies are influenced by factors such as paleogeomorphology, ancient sources, paleo-water depth, and fluctuations in lake levels. Specifically, paleogeomorphology dictates the development position of these sand bodies through trench-channel formations, low-convex-nose-convex-ancient ridges, and their occurrence in underwater uplift and gentle slope uplift areas. Ancient sources determine the scale of development of beach bar sand bodies. Additionally, paleo-depth, as well as the direction of surrounding rivers, lake waves, and coastal lake flow, influence the range from shore to shallow to deep lake, thereby controlling the distribution of beach bar sand bodies. The findings of this study offer insights that may prove valuable for future exploration of oil and gas reserves in beach bar reservoirs with similar geological settings.