SCR (Selective Catalytic Reduction) horizontal reactor

The utility model discloses an SCR (Selective Catalytic Reduction) horizontal reactor which comprises a supporting frame and an overhauling platform, and a plurality of catalyst blocks which are stacked and arranged along the vertical direction are arranged in the supporting frame; the maintenance platform is arranged in the supporting frame along the preset height and located on the maintenance side of the catalyst block so that a plurality of maintenance areas can be formed in the supporting frame in the vertical direction, and a maintenance door is arranged at the position, at each maintenance area, of the supporting frame. According to the SCR horizontal reactor, the height space in the SCR horizontal reactor is divided by the maintenance platform, after a worker climbs up to the maintenance platform through the maintenance door arranged in the maintenance area, the purpose that the catalyst block located at the top is in contact and maintained in the SCR horizontal reactor can be achieved, and the mainte