Abstract: With the continuous increase in the number of automobiles, the market for automotive repair and painting is constantly expanding. Meanwhile, global environmental protection regulations are becoming increasingly strict. Traditional solvent-based automotive touch-up paints, which contain a large amount of volatile substances (VOCs), can cause harm to the environment and human health. Therefore, they are gradually being replaced by water-based touch-up paints. Water-based automotive repair paint, with its environmental protection advantages, has become the development trend of the automotive repair coating industry. However, the application process of water-based touch-up paint still differs from that of traditional solvent-based paint, and it has higher requirements for the construction environment, equipment, process and operators. If the coating process is improper, quality problems such as sagging, color difference and poor drying are prone to occur. Therefore, an in-depth study of the application process of waterbased automotive repair paint is of great significance for improving the quality of automotive repair coating..