Horizontal subsurface flow wetland structure for sewage treatment and construction method thereof

The invention relates to a horizontal subsurface flow wetland structure for sewage treatment and a construction method of the horizontal subsurface flow wetland structure. The scheme comprises the following steps: step 1, constructing a biological treatment area; 2, a first waterproof partition wall is poured on the connecting face of the biological treatment area and the first water collecting well, and a plurality of overflow ports are formed; 3, a permeable concrete partition wall is poured on the connecting face of the first water collecting well and the horizontal subsurface flow purification humid area, steel-plastic grating reinforced permeable concrete partition walls are also poured between different material filling layer areas, and then a slag-slag-gravel mixing layer, a zeolite-volcanic rock mixing layer and an activated carbon adsorption filtering layer are sequentially filled; a horizontal underflow purification humid area is formed; fourthly, a second waterproof partition wall is poured on the