Abstract: The deep-water gravity flow in the middle submember of Member 3, Shanghejie Formation, Jiyang depression was taken as the research object in this study. Based on the differences in sediment composition structure, concentration, transportation-sedimentation mode and fluid rheological characteristics, a study was carried out on the types, sedimentary characteristics and genetic mechanisms of deep-water gravity flow. In the middle submember of Member 3, Shanghejie Formation, Jiyang depression, deep-water gravity flow was classified into debris flow and turbidity current. The former was primarily divided into muddy debris flow with structural matrix effect and sandy debris flow with composition matrix effect based on the matrix content and structure difference in debris-flow sediments; according to trigger mechanism and sedimentary facies sequence characteristics, the latter was divided into two types, i.e., surge-like turbidity current resulting from sediment slump, and quasi-steady turbidity current (density flow) resulting from flood. The sediments of muddy debris flow were mostly composed of thick-massive matrix-supported conglomerate and clastics-bearing sandy mudstone, where there is abrupt contact with top and bottom surface. The sediments of sandy debris flow also mainly consisted of thick-massive sandstones and gravel-bearing sandstones, showing abrupt contact with top and bottom surface and reverse graded bed sequence. Moreover, mudstone tearing clastics and floating boulder clays were mostly developed at the middle and top of sedimentary facies sequence. The sediments of surge-like turbidity current primarily consisted of medium-fine sandstones and siltstones, where complete or incomplete Bouma sequence was developed with scouring-filling structure. The sediments of quasi-steady turbidity current were dominated by gravel-bearing coarse sandstones, medium-fine sandstones and siltstones, and developed in reversed normal graded bed sequence and normal graded bed sequence. In the inner facies sequence, abrupt contact surface or erosion interface was developed with climbing beddings and carbonaceous laminae. The sediments of deep-water gravity flow caused by slumping were dominated by an assemblage of debris flow and surge-like turbidity current, including partial sliding and slumping associated sediments. The sediments of deep-water gravity flow resulting from flood were dominated by an assemblage of debris flow and quasi-steady turbidity current.