As an important layer of the Cambrian oil and gas bearing system in the Tarim Basin, the Shayilike Formation is dominated by high-quality gypsum salt rock caprocks. At present, there is still a lack of research on the types and distribution of sedimentary facies belts in this layer. Based on the core data, logging data, two-dimensional seismic data and high density (five to fifty meters ) microscopic thin section observation data, this paper carried out the study of sedimentary facies evolution and plane distribution characteristics of the Middle Cambrian Shayilike Formation, and summarized the typical lithofacies combination types in the study area. The sedimentary facies are divided according to the seismic facies in the seismic section. The results show that : ( 1 ) The middle Cambrian Shayilike Formation in Tarim Basin develops six sedimentary facies : evaporation platform, limited platform, open platform, platform edge and slope-basin, which can be further divided into nine subfacies including evaporation tidal flat, evaporation lagoon, tidal flat, lagoon and nineteen sedimentary microfacies. ( 2 ) The gypsum rocks and salt rocks in the gypsum-salt lake environment and the dolomite gypsum rocks and gypsum dolomites in the gypsum-salt flat environment around the gypsum-salt lake are mainly developed at the Shayilike period in the western platform of Tarim Basin. ( 3 ) From the west to the east of the basin can be summarized as a typical edged carbonate platform sedimentary model of restricted platform, open platform, platform edge, slope and basin facies.