The invention relates to an environment-friendly water-based nano anti-aging exterior wall coating which comprises the components by weight percent: 15-30% of polyacrylic acid emulsion, 1-5% of film-forming additive, 0.1-0.3% of defoaming agent, 0.5-1% of dispersing agent, 0.1-0.5% of wetting agent, 2-5% of flatting agent, 1-6% of emulsifying agent, 15-25% of titanium dioxide, 2-5% of precipitated calcium carbonate, 0.5-3.5% of mica, 1-3% of zinc oxide, 3-7% of sodium silicoaluminate, 1.5-4.5% of talcum powder, 0.5-1% of thickening agent, 0.3-0.5% of mildew preventive, 10-30% of water, 2-5% of environment-friendly additive and 1-3% of water-based nano anti-aging agent. The environment-friendly water-based nano anti-aging exterior wall coating is good in scuff resistance, high in sandstorm impact resistance and even in coating without crack, can be used for blade coating, roller coating and spraying, has the functions of inhibiting bacteria, dispelling peculiar smell and cleaning air, and is remarkable in anti-man-made aging performance.