The properties of electrophoretic coated products can be reflected in the properties of electrophoretic coatings film,so it is necessary to test the properties of coatings film after the end of electrophoretic coating to verify its quality.After the electrophoretic coating on frame is finished,the thickness,adhesion,appearance and other properties of the electrophoretic coatings film need to be tested on site.The surface roughness of electrophoretic coatings on frame was analyzed by means of gas chromatography and SEM,and the cause of the surface roughness was found and countermeasures was proposed.