Abstract: In the process of natural gas desulfurization by methyldiethanolamine(MDEA), MDEA solvent exhibited higher desulfurization and decarbonization capacity to high sour gas, including higher purification degree, low energy consumption, high stability, corrosion resistance and selectivity. However, for the purification of natural gas containing higher organic sulfur, the desulfurization effect of single MDEA solvent was unsatisfactory. With the commissioning of domestic high sulfur-containing marine gas fields, the development of solvent with higher desulfurization capacity to organic sulfur is more and more important. UDS composite formula solvent developed by East China University of Technology was firstly used in Puguang and Yuanba Purification Plants for high sour gas field in Northeast Sichuan, which achieved satisfactory results.