The reservoir of Huangliu Formation in Dongfang B gas field is a gravity flow submarine fan deposit in shallow sea, with complex sand body distribution and superposition relationship, resulting in strong reservoir heterogeneity and difficulty of characterizing gas-water distribution. Based on the establishment of sequence stratigraphic framework, high resolution facies-controlled seismic waveform indication inversion and well-seismic combinational interpretation are used for fine characterization of sand body. The results show that submarine fan deposits are developed in the lowstand system tract of the Huangliu Member 1, and a set of eroded channel deposition with large sand body thickness and good lateral continuity mainly developed in the low part of Ⅱ-b gas formation, and a set of lobe body deposition with locally developed erosion channels, thin sand body thickness, and poor lateral continuity mainly developed in the upper part ofⅡ-b gas formation. Ⅰ-a gas formation is mainly deposition of distributary channel with thin sand body thickness, which is eroded and cut by the later argillaceous channels and present strong plane segmentation of sand body. It is proved that the distribution characteristics of channels reflected by seismic waveform indication inversion conform to the sedimentary law, and the depiction of sand body boundary can solve the problem of the gas-water distributional contradiction of multiple drilled wells, which is highly consistent with later drilling.