Abstract: The northern slope of Lingshui Sag in Qiongdongnan Basin, as an important replacement area for deepwater oil and gas exploration in South China Sea, has huge hydrocarbon generation potential. Previous exploration practices have shown that this area lacks tectonic traps, and certain breakthroughs have been made in the exploration of lithologic traps in the early stage. However, due to the complex reservoir characteristics, scarcity of drilling data from Sanya Formation, there are significant challenges in reservoir prediction and difficulty in identifying lithological traps. An accurate analysis of sedimentary characteristics and sandbody distribution in this region serves as a critical prerequisite for subsequent trap delineation.This paper makes full use of seismic, drilling and logging data to establish a fine sequence stratigraphic framework. Based on the analysis of paleogeomorphic features, combining the results of longitudinal wave impedance inversion with seismic sedimentology, the reservoirs of the main target layers (Meishan Formation and Huangliu Formation) are identified, their sedimentary characteristics is analyzed, fans of different periods are identified, and the distribution patterns of favorable sand bodies are analyzed. The research results show that the development of fan bodies and the presence of sand bodies in the western part of the study area are both good, making it a favorable area for the next stage of exploration. This research results can provide a basis for subsequent target selection on the northern slope of Lingshui Sag and reduce exploration risks.