Abstract: With many large oil and gas fields having been discovered in the Ordovician marine carbonate rocks in the Tarim and Ordos basins, however, no substantial breakthrough has been made in the oil and gas discoveries in the Ordovician of the Sichuan Basin. Previous exploration focused on karst and fractured reservoirs, and only a few wells were found to have natural flow. Whether there is grater potential of large-scale exploration potential beach reservoirs in the Ordovician of the Sichuan Basin is an urgent question to be answered. Due to the rapid change of lithology, the sedimentary system of the Ordovician is still controversial, which limits the understanding of potential reservoir facies belts to some extent. Based on logging, seismic, and outcrop profile data, the characteristics of Ordovician sedimentary facies in the Sichuan Basin are analyzed, and the lithofacies paleogeographic pattern of each sedimentary period is reconstructed. The results show that during the sedimentary period of the Tongzi–Honghuayuan formations, the Yangtze plate, where the Sichuan Basin is located, was influenced by the Pan-African movement, and the upper Yangtze structure was relatively stable. The dominant sedimentary facies was a carbonate platform, and the sedimentary model was an epigenetic shallow platform. Beach facies dolomite distributed around the periphery of the Leshan-Longnüsi palaeouplift. During the sedimentary period of the Meitan Formation, due to the rise in global sea level, the tectonic environment changed into a strong compressive background dominated by the Caledonian movement, the uplift and depression pattern was intensified, and the sedimentary environment was mainly mixed shelf. In the sedimentary period of the Shizipu–Baota–Linxiang formations, carbonate deposits dominated by limestone redeveloped, representing an epigenetic carbonate gentle slope environment. During the sedimentary period of the Wufeng Formation, the Caledonian movement led to the formation of a limited deep-water bay environment in the southeast Sichuan Basin, where a set of organic-rich shales were deposited. In general, the Ordovician sedimentary evolution in the Sichuan Basin has undergone a process from epicontinental shallow platform to mixed shelf, then to epicontinental gentle slope, and finally to lingering deep shelf.