The invention relates to an elemental mercury oxidation device comprising a reactor body, the lower part of the side wall of the reactor body is provided with an air inlet, the upper part of the side wall of the reactor body is provided with an air outlet, an oxidation solution is in the reactor body, the reactor body is internally provided with a spraying rod, the spraying rod is provided with a plurality of nozzles, the nozzles are used for up spraying of the oxidation solution to form an oxidation solution curtain bed, the spraying rod is connected with a circulating pump, a mercury detector is arranged on the air outlet, and the oxidation solution is a bleach powder solution. The elemental mercury oxidation device has the advantages of simple structure and strong operability, the nozzles on the spraying rod are used for continuous up spraying via the circulating pump of the oxidation solution to form the oxidation solution curtain bed for washing flue gas containing mercury so as to remove mercury element in the flue gas containing mercury, the reactor body is connected with an absorbent electrolytic regeneration pool, and can be used for absorption liquid regeneration and the recovery of the elemental mercury, the rational use of resources can be achieved, and environmental pollution can be reduced.