Abstract: The organic sulfur content in sulfur recovery and tail gas treatment unit of natural gas purification plant has an important influence on the emission reduction of sulfur dioxide.Research showed that the organic sulfur can be produced in the combustion furnace, catalytic reactor and the hydrogenation hydrolysis reactor of the tail gas treatment unit.The formation of organic sulfur can be effectively reduced by reducing hydrocarbon content in acid gas, increasing the temperature of the combustion furnace, selecting suitable type of catalyst and maintaining the high hydrogenation hydrolysis reaction temperature.Meanwhile, for the organic sulfur generated in the process, following countermeasures can be adopted to reduce the content of organic sulfur into the incinerator to the lowest level to achieve standard discharge of the tail gas:(1) Optimize the catalyst combination method; (2) superimpose hydrolysis in the reactors at all stages; (3) maintain the high efficient conversion in the hydrogenation hydrolysis unit.