To investigate the epigenetic alteration zoning of sandstones in the Sifangtai Formation of the Sanzhao area and summarize the uranium metallogenic regularities, a large number of continuously cored borehole cores was taken as the basis. Sandstones of different lithogeochemical types from the Sifangtai Formation in the study area, including brownish-red sandstone, grayish-green sandstone, gray ore-bearing sandstone and gray barren sandstone, were selected as research objects. On the basis of macroscopic petrological characteristics such as rock color and type reflected by borehole cores, microscopic features of sandstones with distinct lithogeochemical types and mineralogical characteristics of epigenetic alteration were identified via laboratory analyses using polarizing microscope, scanning electron microscope ( SEM ) and other technical methods. Major element chemical analysis and environmental sensitive parameter analysis were conducted to investigate the geochemical characteristics including elemental composition and content of various sandstones. In particular, characteristic elements such as organic carbon, sulfur, the ratio of ferric iron to ferrous iron, thorium and uranium were analyzed to clarify the similarities and differences in geochemical features among different sandstone types. Petrological and geochemical indicators for epigenetic alteration zoning of the Sifangtai Formation in the study area were preliminarily established, and the corresponding zoning model was summarized. For the first time, a preliminary division of epigenetic alteration zones for the Sifangtai Formation was carried out based on sandstones of different colors in this area. It is confirmed that uranium orebodies are mainly distributed in the redox transition zone, which provides a guiding reference for uranium exploration in the study area.