Black rock series, which are widely distributed in Southwestern China, Distribute mainly in the upper SinianLower Cambrian, Silurian system, Permian and Triassic. Among them, the major strata is the upper Sinianlower Cambrian, followed by silurian system. In the black rock series in Southwestern China, there are many typical deposits, with many similar characteristics, has close relationship with the regional deep fault, lithology, magmatismfluid activity. Numerous Uranium deposits, uranium occurrences and mineralized spots are widely distributed in the black rock series. In the black rock series in Southwestern China, there are many typical deposits, such as Zoige deposit (510) of Sichuan, Baimadong deposit in （504） Guizhou and Daxin deposit（373）of Guangxi. In Southwestern China, higher concentration of uranium in black rock series by sedimentation and Diagenetic stage is the prelude of the black rock seriestype uranium deposits. The metallogenic way and scale of reformation and superposition are essential condition for the formation of rich and large deposit in black rock series. A necessary "trilogy" to the formation of rich and large deposit in Southwestern China: Prelude: High value area of uranium content by sedimentation (uranium mineralized spots and "abnormal area" of uranium); Reformation: Second uranium enrichment by the transformation of shallowsourced fluid (small or mediumsized uranium deposits, uranium occurrences); Superposition: Formation of rich and large deposit by the superposition of deepsourced fluid (largescale uranium deposits).