The invention relates to an anti-sagging APAO-modified alkyd resin water-based functional coating. The coating comprises, by weight, 50.0-70.0 parts of APAO-modified water-based alkyd resin, 15.0-30.0parts of silicon-modified waterborne alkyd resin, 3.0-6.0 parts of an anti-freezing agent, 0.3-0.8 part of a thickener, 0.0-25.0 parts of a pigment filler, 0.0-0.8 part of a dispersing agent, 3.0-8.0parts of a coalescing agent, 0.1-0.4 part of an antifoaming agent, 0.2-0.5 part of a leveling agent, 0.1-0.5 part of a wetting agent and 8.0-20.0 parts of deionized water, wherein the APAO-modified waterborne alkyd resin is prepared from vegetable oil fatty acid, maleic anhydride-grafted APAO, polybasic acid, polyhydric alcohol, n-heptanoic acid, dimethylolpropionic acid and a neutralizer througha reaction. The anti-sagging APAO-modified alkyd resin water-based functional coating prepared by the invention has the characteristics of good sagging resistance, good adhesion, high hardness, goodmechanical properties, high crosslinking density, good water resistance and the like.