Abstract: In order to clarify the coexisting relationship between the coal, pyrite and other reducing medium in Yan'an and Zhiluo Formation and the sandstone uranium deposit in Tarangaole area, the ore-bearing sand body, pyrite and carbon debris in Zhiluo Formation and coal seam in Yan'an Formation were selected as the research object, a series of test including drilling core catalog, microscope analysis and electron probe analysis were used to carry out research. It has been shown that the uranium ore body, coal seam in Yan'an Formation, carbon debris in Zhiluo Formation are vertically stacked and related in genesis, the coal deposits of Yan'an Formation provide a large amount of reducing agent for uranium deposits, while the humic acid in the charcoal of Zhiluo Formation mainly played the role of adsorption and complexation; Coffinite is the main uranium ore type and has connection with framboidal pyrite, altered massive pyrite, colloidal pyrite, ilmenite, leucoxene; The amount of reducing medium and spatial distribution can be used as indicator of uranium mineralization.