The Huanggang Sn-Fe deposit in Inner Mongolia is one of the important skarn deposits in Southern Great Hingganling polymetallic belt.Lower Permian Dashizhai Formation and Huanggangliang Formation are the main ore-hosting horizons. Ore bodies are largely concordant with the bedding of the strata, and the distribution of the ore bodies is spatially related to skarn. The formation of the Huanggang ore deposit experienced skarn phase, retrograde eroding phase, quartz sulfide phase and carbonate phase. Petrographic and microthermometric studies of fluid inclusions in garnet, epidote, hornblende, quartz, calcite and fluorite from different phases show that the inclusions related to mineralization include mainly silicate melt inclusions, H2O-NaCl type inclusions, CO2-H2O±CH4 type inclusions and CO2-H2O-NaCl type inclusions.