Preparation method of waterborne polyurethane coating with high weather resistance and salt spray resistance

The invention discloses a preparation method of a high-weather-resistance and salt-fog-resistance waterborne polyurethane coating, which comprises the following steps: S1, firstly, pretreating all raw materials in base paint of the coating, removing impurities from the raw materials, filtering and dehumidifying, and simultaneously, respectively carrying out inert reaction on polyether polyol and polyisocyanate to form isolates; aging of the coating can be effectively slowed down by adding the ultraviolet light absorber and the antioxidant, so that the weather resistance of the coating is improved, the ultraviolet light absorber UVP-327 is good in chemical stability and extremely low in volatility and is especially used for polyurethane, and the polarity of the whole polyurethane coating can be improved by adding the polar solvent methyl alcohol, so that the weather resistance of the coating is improved. The higher the polarity of the polyurethane coating is, the more beneficial to salt fog resistance is, and