U, Mo, Ni, Re and Tl elements are enriched in the Ni- Mo polymetallic layer of the Lower Cambrian Niutitang Formation in the Songlin area of Zunyi, Guizhou Province. In this paper, the phosphorite of Ni- Mo polymetallic layer in the Songlin area is taken as the main research object. Chemical analysis, track etching, scanning electron microscopy and energy spectrum scanning, leaching experiment were carried out, based on the sampling of profile system in the Songlin area. The results show that Ni and Mo reached industrial grade, while U, Re and Tl are significantly enriched in the Niutitang Ni- Mo polymetallic layer of the Lower Cambrian. Trace etching experiments show that uranium is mainly enriched in the organic carbon extranet at the clastic edge of phosphorite block, and the key observation area is delineated for further determining the occurrence form of uranium. The uranium in the Ni- Mo polymetallic layer in this area is in the form of uraninite and occurs in the corrosion hole, micro- cracks or micro- pores of the dissolved and recrystallized phosphorite, and is symbiotically associated with medium and high temperature hydrothermal minerals such as stileite, arsenopyrite, sphalerite, galena and apatite. Deionized water, H 2SO 4, NaHCO 3+MnO 2 were used to leach uranium in water soluble, acid soluble and oxidized soluble state. 48 hours leaching experiment at 80℃ shows that the color of polymetallic phosphorite fades from black to light gray, while the color of carbonaceous shale is black before and after the experiment. The uranium in the Ni- Mo polymetallic layer and carbonaceous shale in the Zunyi area mainly exists in the form of adsorption or independent minerals, while the proportion of insoluble uranium in the form of isomorphism is less. It is concluded that uranium in the polymetallic phosphorite in this area exists as an independent mineral in the middle and high temperature hydrothermal mineral symbiosis, which provides new microscopic evidence for revealing the submarine jet and hot water deposition in the marginal rifting environment of the eastern margin of the Yangtze block.