In view of the fact that the automobile coating wastewater contains resin, surfactant, heavy metal ions, oil, pigments and other pollutants, especially the complex composition, high concentration and poor biodegradability of the electrophoresis wastewater and paint spraying wastewater, the coating wastewater is treated by mass separation, coagulation sedimentation, coagulation flotation, sand filtration and other processes, and good results are achieved: CODCr removal