Based on analysis of water utilization and high efficient circulating water techniques for washing car, the efficient-circulation washing technology, In view of the current problems in car washing industries,such as high water consumption and washing wastewater pollution of the environment, the technological process, technical characteristics, running condition and treatment effects of circulating water appratus for washing car were analyzed based on the WR-RO and WR-UF techniques. Wastewater originated from car washing contains many impurities, such as free oil, oil emulsion, clay sludge, surfactant and other soluble organic matters. By using ultrafiltration as the key treatment process of car washing wastewater, the removal rates of turbidity, COD, and anionic surfactant were 98%, 68%, and 69%, respectively. The high efficient circulating water technology for washing car has the characteristics of strong operability, water quality safety, low running cost and considerable benefit, and has important extention values.