The sedimentary environment of bauxite in Wuchuan-Zheng’an-Daozhen Area has been debated for a long time. Through research on the element B, the sedimentary characteristics of bauxite, the distribution of four different natural types of bauxite and reference paleogeographic data we concluded that bauxite in Wuchuan-Zheng’an-Daozhen Area was a typical sedimentary deposit, with a provenance mainly from south-west. Bauxite was formed in an anoxic bay, which was partly closed and open to north. The sedimentary environment shifted between lacustrine and bay environments, accompanying frequent transgression and regression cycles.