Abstract: Weixi'nan Sag of Beibu Gulf Basin has good oil and gas accumulation conditions. As one of the main exploration strata, the lithology of Weizhou Formation, varies greatly and the tectonic setting is complex. Conventional logging, analysis and laboratory data can not meet the needs of source direction and sedimentary microfacies analysis in oil and gas exploration. On the basis of the geological research in the area, through the analysis of key geological information such as static images and dip vectors in the electric imaging logging data, the imaging logging research of the sedimentary facies of Weizhou Formation was carried out. In this paper, the lithological interface of the sand and mudstone was determined, and various sedimentary structures such as horizontal bedding and cross-bedding were identified. At the same time, the paleocurrent direction in the study area was analyzed: the dominant directions were north-west and north-east. Imaging interpretation plates of the sedimentary microfacies of the branch channel and underwater branch channel were established. The research results play an important role in the deepen study of the sediments of Weizhou Formation in Weixi'nan Sag and the further implementation of provenance direction. They also provide certain technical support for next oil and gas exploration and deployment of the sag.