Provided is a multifunctional paint auxiliary agent. The multifunctional paint auxiliary agent is prepared from the following raw materials, by weight, 8-14 parts of polyacrylic acid, 4-7 parts of diethylene glycol, 2-4 parts of sodium carboxymethyl starch, 6-20 parts of nano-slurry, 7-13 parts of Arabic gum, 2-8 parts of carrageenan, 9-15 parts of silver-carrying nano-zirconium phosphate, 5-7 parts of nano-silicon oxide, 3-9 parts of surfactant, 0,1-0.2 part of emulsifier, 6-8 parts of acrylic acid ester acrylate ester compounds, 14-22 parts of pearl mica, 6-9 parts of glass bead, 5-12 parts of nano-zinc dioxide, 0.8-7.5 parts of 2-hydroxy-4-methoxy benzophenone and 4-8 parts of monoglyceride stearate. The beneficial effects are that the multifunctional paint auxiliary agent has functions of mildew resistance, corrosion resistance, washing resistance, stain resistance and anti-oxidation, and can raise and improve performances of paint and films effectively, and high efficiency and environmental protection are achieved.