Abstract: The effects of atmosphere, temperature and catalysts on the BRXL lignite liquefaction conversion and the yield of oil, gas, and water were studied with syngas and complex solvents (water+organic solvent), and the characteristics of BRXL lignite liquefaction were also discussed. The results show that the atmosphere of syngas and the temperature of 430-450℃ are beneficial to coal liquefaction reaction under complex solvents system with catalyst. The coal conversion is 81.15%, and the yield of oil, gas, and water reaches to 71.53%. Besides, the composite catalyst (including iron, base, and sulfur) can effectively improve the coal conversion and the yield of oil, gas, and water. The coal conversion and the yield of oil, gas, and water at 430℃ reach to 92.27% and 79.39%, respectively. Also, the composite catalyst can effectively promote the cracking of macromolecules in coal and the enhancement of water-gas shift reaction, resulting in a decrease of asphaltene and an increase of oil yield. Moreover, the polycyclic aromatic hydrocarbons and derivatives in liquefaction oil can be converted to monocyclic aromatic hydrocarbons and derivatives and alkenes olefins during catalytic liquefaction, resulting in a decrease of compound molecular weight and an improvement of oil quality.