The utility model relates to a car washer for industrial area ground is executed to foundation ditch, washing unit including the car washing pool cell body and the outside, the car washing pool cell body is formed by a plurality of regular set water sedimentation unit assembly, regular set water sedimentation unit includes the steel sheet of complex root H shaped steel roof beam and these a little H shaped steel roof beams of connection and welds in the drain pipe of these unit both sides, the steel sheet welds in the lower flange of these a little H shaped steel roof beams and both ends face, all be equipped with the flange on the drain pipe, the top of regular set water sedimentation unit is equipped with rigid coupling in the apron of H shaped steel roof beam, should lap to assemble a bit to become to be open to traffic the way board. The utility model discloses outside guaranteeing the current function of vehicle, can have enough to meet the need the use, the flexible package, and the ability using water wisely can reduce material and artificial use amount effectively, demolishs reinforced concrete structure's manual work, mechanical stage class and building rubbish simultaneously after the less project.