The invention discloses a hydroxypolyacrylate emulsion, and a preparation method and an application thereof. The preparation method comprises the following steps: weighing an acrylate monomer and/or a metacrylate monomer, a hydroxyacrylate monomer, an acrylic monomer, an acrylate function monomer and a hydroxy oligomer, uniformly mixing to prepare a monomer mixture, weighing 10-15% of the monomer mixture, and emulsifying by using an emulsifier to prepare a seed pre-emulsion for later use; and adding the emulsifier, sodium bicarbonate and deionized water into a reaction kettle, stirring, rising the temperature of a reaction system, adding an initiator, stabilizing, adding the seed pre-emulsion in a dropwise manner, stabilizing, adding the remaining monomer mixture and the remaining initiator in a dropwise manner, heating, slaking, cooling, neutralizing, carrying out heat insulation, cooling, and discharging to obtain the hydroxypolyacrylate emulsion. A film made by using an aqueous dual-component polyurethane coating prepared from the hydroxypolyacrylate emulsion and an aqueous polyisocyanate curing agent has the advantages of high hardness, high luster and excellent chemical resistance.