For Color Coated Galvanized Steel Coil, During the coating operation, the operator uses a coating thickness gauge to measure the wet film thickness of the coated steel surface coating. According to the measured wet film thickness and the known corresponding ratio of dry film thickness to wet film thickness, the gap of the relevant rollers and the rotational speed of the relevant rollers are adjusted through the computer sensor, and the coating roller, the drawing roller, and the roller are adjusted within a certain range. The speed of rotation of the rollers is adjusted, thereby changing the thickness of the paint. This method is more timely after measuring the dry film thickness and then adjusting the coating thickness, but it requires extensive experience.