The Miaoliang gold deposit is located in the center of the Southern Qinling Zhashui-Shanyang ore concentration area. In order to find out the characteristics of ore-forming fluids, the precipitation mechanism of gold and genesis of the Miaoliang gold deposit, the fluid inclusions in gangue minerals at different metallogenic stages of the deposit were studied in detail by petrography, microthermometry, laser Raman spectroscopy, comparing with the characteristics of typical surrounding gold deposits. The results show that the deposit is rich in types of inclusions. The early stage of mineralization is mainly H₂O-NaCl type inclusions (type Ⅱ), part of H₂O-CO₂ type inclusions (type Ⅲ) and a small amount of pure CO₂ type inclusions (type Ⅰ); the main metallogenic stage is mainly H₂O-NaCl type inclusions (type Ⅱ) and H₂O-CO₂ type inclusions (type Ⅲ); the late mineralization stage is mainly H₂O-NaCl type inclusions (type Ⅱ). Microscopic temperature measurements show that from the early stage to the late stage, the fluid properties evolve from medium and high temperature, medium salinity, low density, CO₂-rich fluid to medium and low temperature, medium-low salinity, medium density and CO₂-poor fluid. Laser Raman analysis shows that the gas phase of inclusions contains a certain amount of CH₄ and H₂S in addition to CO₂. Comprehensive study concluded that gold migrates in the form of Au(HS)₂^- complex in the fluid under the reduction environment of low oxygen fugacity, and that immiscibility due to the decrease of temperature and pressure is the main mechanism of gold precipitation in the process of fluid upward migration.