Abstract: To finely characterize the lithological and lithofacies features, sedimentary environment characteristics, and evaluate the seal capacity of shallow gas reservoirs in the ultra-shallow layers of the Ledong Formation in the Lingnan Low Uplift area of the Qiongdongnan Basin, high-resolution resistivity imaging logging technology was introduced into comprehensive geological evaluation studies of ultra-shallow reservoirs for the first time. The results indicate that the lithology of the ultra-shallow reservoirs in the Ledong Formation primarily consists of fine sandstone, siltstone, and argillaceous siltstone, with four types of sandstone lithofacies, two types of mudstone lithofacies, and mixed accumulation lithofacies being developed. Based on the comprehensive lithofacies and regional geological background, the ultra-shallow reservoirs in the study area are mainly characterized by depositional microfacies such as mid-fan distributary channels and sheet sands within submarine fans, overlain by thick deposits of deep-sea mudstone, indicating a favorable reservoir-caprock configuration. The degree of natural fracture development in the study area is relatively weak, and horizontal bedding is observed in the mudstone, suggesting a stable post-depositional tectonic environment conducive to the preservation of ultra-shallow gas reservoirs. Additionally, the ultra-shallow reservoirs have undergone significant deformation due to massive deposition transport (MDT) modification, resulting in poorer reservoir properties and the formation of local caprocks for the ultra-shallow gas reservoirs. The application of high-resolution resistivity imaging logging technology in evaluating the geological characteristics and seal capacity of ultra-shallow reservoirs compensates for the lack of core data due to the shallow burial and loose structure of these reservoirs and provides strong geological evidence for subsequent well location deployment.