The invention provides a waterborne metal baking varnish. The metal baking varnish comprises, in parts by weight, 10-40 parts of a waterborne acrylic resin, 10-30 parts of a waterborne polyester, 5-20parts -of an amino resin, 5-15 parts of a co-solvent, 0.2-0.5 part of a wetting agent, 0.2-0.4 part of an anti-foaming agent, 0.3-1.5 parts of a thickener, 0.05-0.3 part of a catalyst, 0.1-0.5 part of a pH adjuster, 0-4 parts of an aluminum silver paste, and water. Compared with an oil paint, the provided waterborne metal baking varnish is more environment-friendly and yellowing-resistant, and has relatively strong hardness, water resistance, chemical resistance and other properties. Compared with an ordinary waterborne metal baking varnish, the waterborne metal baking varnish has a lower baking temperature, and has relatively strong tolerance at baking temperature and baking time. At the same time, a paint film has high hardness, strong flexibility, and strong adhesion and salt fog resistance, operability and controllability in use are greatly improved, and popularization and use are easier.