Abstract: The Yanlong bauxite deposit is a recently discovered super-large bauxite deposit. By analysis and comparison of a large number of drill core data, it is considered that there existed three main types of sedimentary environment in the area, namely barrier island facies, shallow lake-lagoon facies, and tidal flat-swamp facies. In local barrier island environment, there is no sedimentary mineralization. It is easy to deposit and mineralize in the shallow lake-lagoon environment, in which the thickness of bauxite is moderately correlated with that of ore-bearing rock series. In the tidal flat-swamp environment, the conditions for sedimentary mineralization are poor. The paleogeographic characteristics of Yanlong area in Late Carboniferous determine the thickness of ore-bearing rock series, yet not directly control the mineralization thickness of bauxite. Instead, it indirectly controls the formation by affecting the sedimentary environment combined with other metallogenic conditions.