Abstract: In order to solve the problem of recovery and treatment for sulfide in the waste gas of liquid sulfur degassing of sulfur recovery unit in natural gas purification plant and reduce the pollutant discharge, the waste gas composition of liquid sulfur pool was detected by field sampling. According to the characteristics of liquid sulfur degassing process and waste gas composition in natural gas purification plant, three schemes including introducing the waste gas of liquid sulfur pool into combustion furnace, Claus reactor and hydrogenation reactor were calculated and studied separately by professional sulfur recovery software. The influence on the operation parameters and total sulfur recovery rate of units were compared. Three technical schemes suitable for the waste gas treatment of liquid sulfur degassing in natural gas purification plants were proposed. In addition, the waste gas recovering treatment process from liquid sulfur pool by fixed bed catalytic conversion was also studied. At the same time, it was predicted that one of the development trends of reducing the emission of sulfur-containing pollutants in the future was the treatment of liquid sulfur degassing or waste gas after degassing by various combined processes.