Car washing pipeline circulating water system

The utility model discloses a car washing pipeline circulating water system which is characterized in that a pair of retention walls extend along the driving direction of a car to be washed and are arranged at intervals; the infrared sensing device is fixed to the retention walls and faces the interval between the pair of retention walls. The drainage ditch is transversely connected to the pair of retention walls and has a preset gradient; the annular galvanized pipes are fixed to the upper surfaces of the water retaining walls correspondingly, the water outlet nozzles are fixed to the annular galvanized pipes, the spraying directions of the water outlet nozzles face a to-be-washed vehicle located between the water retaining walls, the water supply pipe is in liquid communication with the annular galvanized pipes, and the water pump is communicated with the water supply pipe. The sedimentation tank is in liquid communication with the drainage ditch and comprises a first-stage sedimentation tank in liquid comm