Objectives: The Danzhai gold—mercury deposit is located in the Sandu—Danzhai gold—mercury—antimony polymetallic metallogenic belt. The studies on gold deposits of Guizhou focus on the Southwest in Guizhou. However, there is no systematic study on Danzhai gold deposit so far. Geological, geochemical characteristics and genesis of the paiting gold—mercury deposit in Danzhai are studied in this paper. Methods: Field investigation and systematic sampling were carried out in this paper. Thin section from six samples for electron probe analysis of sulfides. Cinnabar from three samples of mercury ore for sulfur isotope analysis. Calcite from eight samples for carbon and oxygen isotopes analysis. Organic carbon from four limestone samples for carbon isotopes analysis. Results: Electron probe analysis shows that: Pyrite has different shapes in different stages and the content of each element is different. Au content in cinnabar is lower than the detection limit, and arsenopyrite is the main goldbearing mineral. δ34SV-CDT (δ34SCDT) of cinnabar and stibnite varies from 20.63‰ to 23.53‰, δ13CV-PDB of organic carbon varies from -29.78‰ to -30.45‰, δ13CV-PDB of calcite varies from -0.56‰ to -5.97‰，δ18OV-SMOWvaries from 15.23‰ to 20.14‰. The results show that: The sulfur of cinnabar and stibnite is mainly strata sulfur and biogenic sulfur; the oxygen of calcite comes from the surrounding rock; the carbon of metallogenetic fluids from multiple sources and organic carbon is one of the necessary sources. Conclusions: Pyrite is divided into diagenetic period pyrite and hydrothermal period pyrite. Hydrothermal period pyrite includes early metallogenetic stage pyrite (PyⅠ), main metallogenetic stage pyrite (PyⅡ) and late metallogenetic stage pyrite(PyⅢ). Arsenopyrite is the main goldbearing mineral. The sulfur of cinnabar and stibnite is mainly strata sulfur and biogenic sulfur. The metallogenetic fluids is mainly magmatic hydrothermal, which combined with some meteoric precipitation. The carbon in metallogenetic fluids may comes from a mixture of different endmember fluids, and the oxygen comes from surrounding rocks. Gold, antimony and mercury the Paiting gold—mercury deposit of are formed successively and belong to different metallogenic stages. Gold element is mainly derived from hypomagma, and the gold mineralization is related to magma. However, mercury is mainly derived from the strata, and the mercury mineralization is related to the the dissolution of carbonate rocks and the dehydroxylation of deposited organic matter. The sulfur of the mercury ore and antimony ore is mainly strata sulfur and biogenic sulfur.