Through studying on the ultrafiltration membrane separation technology in the electrophoretic painting concrete scene,the fresh ultrafiltrate was prepared in the laboratory simulation.Then ultrafilate parameters were determined using pH meter and conductivity meter,organic small molecule components were analyzed by gas chromatograph,and element components was determined by X-ray fluorescence analyzer.A variety of methods combined to determine the the specific components of ultrafiltration fluid?so that the ultrafiltration technology to achieve the closed cleaning afterelectrophoresis,reduce the wastewater production and improve the utilization rate of paint The control of the electrophore sistank liquid and paintfilmquality wasrealized.