Assembled corrosion-resistant water tank for domestic sewage treatment

An assembled corrosion-resistant water tank for domestic sewage treatment comprises eight first tank body units, the eight first tank body units are assembled into the water tank through fasteners, a water inlet pipe opening and a water outlet pipe opening are formed in the water tank, each first tank body unit comprises a first outer wall unit and a first inner wall unit, and a connecting plate is arranged on the edge of each first outer wall unit; the edge of each first inner wall unit is provided with a turned-over edge, the first inner wall units are attached to the interiors of the first outer wall units, the turned-over edges are located on the outer sides of the connecting plates, and the connecting plates of the adjacent first outer wall units clamp and fix the turned-over edges of the first inner wall units in the first outer wall units. In the carrying process, the water tank can be carried in units and then assembled after being carried to the site, and therefore the problem that a new water tank c