Abstract: As mercury in natural gas is always toxic and corrosive, it would bring security risks to staff and production equipment. According to the study of mercury distribution law in natural gas treatment unit, it can provide basis for the development of corresponding mercury prevention measures subsequently. The mercury distribution in the TEG dehydration unit was simulated and analyzed, and it was found that the mercury absorption effect of TEG on feed gas was weak, but the mercury concentration in flash gas and regenerated gas was higher. The mercury contribution in TEG dehydration unit under different conditions such as different mercury concentration of feed gas, different lean TEG circulation volume and different rebolier temperature was studied. According to the simulation and analysis results of mercury distribution in the TEG dehydration unit, some mercury pollution control measures were put forward such as moisture mercury removal, cleaning of mercury-containing equipment and staff protection, disperse mercury treatment, which could provide mercury prevention references for follow-up construction of mercury-containing natural gas treatment plants.