Various forms of mercury are contained in the gas field wastewater with the production and development of the mercury-containing gas field.Direct discharge of unqualified mercury-containing wastewater without treatment will cause serious damage to the ecological environment. The treatment of mercury-containing wastewater should combine oil & water separation technology with mercury removal technology. In practical engineering applications, different treatment processes are often selected to treat mercury-containing gas field wastewater according to the different quality of raw water.In foreign gas fields, gravity sedimentation-flocculation, flocculation-air flotation and flocculation-adsorption processes have been successfully used to treat mercury-containing gas field wastewater.After treatment, the mercury content in purified water can be reduced to the level of ug/L.Drawing lessons from the experience of foreign mercury-containing gas field wastewater treatment projects and combining with the actual situation of domestic mercury-containing gas fields,it is of great practical significance to strengthen the research and application of mercury-containing gas field wastewater treatment technologies, to rationally develop mercury-containing gas fields in China and to reduce the hazardrm of mercury-containing gas field wastewater.