The utility model relates to a three check sedimentation tanks for building site, this three check sedimentation tank are located the below ground, include pool wall (1), establish inlet tube (3), outlet pipe (9) on the pool wall and establish in pond intramural twice partition wall (5), all be equipped with square hole (8) that supply the fluid circulation on per pass partition wall (5). Compared with the prior art, the utility model discloses precipitation efficiency is high, the security is high, do not have the short turbulent phenomenon that flows, can finely be applied to building site sewage treatment field.