The Dengying Formation and Laobao Formation are important Ediacaran-Cambrian stratigraphic units in South China. We report here integrated zircon cathodoluminescence (CL) and U-Pb isotopes of tuff from the platform facies in the Xinzhai section located in the Yankong area of northern Guizhou, and Jianfengding and Wangjianshan sections located in the Songlin area of northern Guizhou, and from the transition zone in the Niujiaochong and Xinchong sections located in the Pianyan area of eastern Guizhou, and from the slope facies in the Guabang section located in the Sanshui area of southeast Guizhou. Zircon LA-ICP-MS U-Pb dating results show that the tuff layers of Xinzhai, Wangjianshan and Xinchong sections were formed at 532±4 Ma, 536±5 Ma and 535±4 Ma, respectively, and the tuff layers of Jianfengding, Niujiaochong and Guabang sections were deposited at 520±4 Ma, 517±3 Ma and 521±3 Ma, respectively. Synthesis of previous results and this study show that the deposition time of the Dengying Formation and Laobao Formation are constrained from 551.1±0.7 Ma to 518±5 Ma, and 550.6±3.3 Ma to 517±3 Ma, respectively. Which belong to simultaneous heterogeneous sedimentation. The uranium-rich phosphorite within the Laobao Formation and equivalents in the Yankong, Songlin and Pianyan areas were formed between 546.3±2.7 Ma and 532±4 Ma, 536±5 Ma to 520±4 Ma and 535±4 Ma to 517±3 Ma, respectively.