Weather-resistant exterior wall topcoat varnish is refined from advanced polymer emulsion and functional additives. It can effectively resist ultraviolet radiation and slow down color fading. As a key part of modern building exterior wall decoration, it not only endows buildings with a brilliant and colorful appearance, but also provides a solid protective coat for buildings with its excellent weather resistance, anti-fouling property and chemical corrosion resistance. It can also maintain the gloss and integrity of the paint film and extend the aesthetic period of the exterior wall.