The invention discloses a weather-proof firing-resistant powder coating which comprises the following components in mass fraction: 15-30% of silicone resin, 10-20% of modified acrylic resin, 15-30% ofamorphous silicate, 5-15% of a phosphate compound, 5-15% of ultrafine silica, 2-10% of an environment-friendly high-temperature-resistant pigment, 0.1-0.5% of blocked isocyanate and 0.2-10% of an auxiliary agent. The invention also discloses a preparation process of the weather-proof firing-resistant powder coating. The powder coating provided by the invention has good weatherability and firing resistance, and can be widely applied to the fields of products such as barbecue ovens, fireplaces, chimneys and exhaust pipes.