Water-based finishing paint for plastics and preparation method and application thereof

The invention relates to a water-based finishing paint for plastics and a preparation method and application thereof; the water-based finishing paint comprises a hydroxylated acrylic resin, a wetting agent, a flatting agent, a deforming agent, deionized water and an aliphatic polyisocyanate curing agent; the preparation method comprises the following steps of: firstly, weighing the hydroxylated acrylic resin according to a formula dosage, then adding the wetting agent, the flatting agent and the deforming agent under high-speed stirring, uniformly mixing and stirring, then adding the deionized water to dilute a mixture, slowly adding the aliphatic polyisocyanate curing agent under the stirring state, stirring till the raw materials are uniformly mixed, adjusting viscosity to be 13-22 seconds (testing under a 25-DEG C normal temperature by using an NK-2 IWATA cup), filtering, discharging, and preparing the water-based finishing paint for plastics; and when being applied, the water-based finishing paint for plastics is coated on a priming paint of a plastic shell such as a shell of a cell phone, a shell of a panel personal computer and the like. The water-based finishing paint is non-corrosive as water is used as a dispersion medium and solves the problem of difficulty to adhere of the water-based finishing paint by adopting the hydroxylated acrylic resin; and the large-batch production of the water-based finishing paint is easily realized, and the properties of the water-based finishing paint product are stable.