The utility model discloses a sedimentation tank device of wall is depositd in area, including the sedimentation tank, being provided with into on length direction's two inside walls of sedimentation tank edge respectively, water water distribution trough compiles the canal with play water, be provided with perpendicularly along length direction in the middle of in the sedimentation tank and install sedimentation tank bottom, the inclined hole of separating the sedimentation tank for two parts deposit the wall, the inclined hole deposits certain angle ground that inclines on the wall and evenly is provided with the sediment passageway that runs through the inclined hole and deposit the wall both sides, and the water distribution trough bottom that intakes is equipped with a plurality of downwardly extending's the distributing water pipe of intaking along length direction, and the perforated sludge discharge pipe of one end outside extending to the sedimentation tank is installed respectively in the both sides that the inclined hole deposits the wall in the sedimentation tank bottom. The utility model provides a being difficult to even water distribution and catchmenting, shortly in the pond flow that the phenomenon is many, the ni qu blind spot is many, the heavy mud emission in bottom is difficult, scrape and inhale a mud device structure difficult problem such as hard of existence such as horizontal flow sedimentation tank commonly used, vertical flow settling pond, radial flow sedimentation tank, area is few, has reduced civil engineering and equipment cost.