The invention provides a preparation method of a plant oil-based aqueous polyurethane coating and the coating prepared through the preparation method, and relates to the technical field of aqueous polyurethane coatings. According to the preparation method of the plant oil-based aqueous polyurethane coating, plant oil-based polyol and diisocyanate are mixed in acetone and catalyzed and pre-polymerized through dibutyltin dilaurate, and prepolymer mixed liquor is obtained. A hydrophilic chain-extending agent and hydroxyethyl acrylate are added in the prepolymer mixed liquor to be polymerized, and polymer mixed liquor is obtained. The polymer mixed liquor is neutralized to be neutral through triethylamine, deionized water is added for shearing and emulsifying, and then the acetone is removed, and the plant oil-based aqueous polyurethane coating is obtained. The preparation method is easy to operate, the prepared plant oil-based aqueous polyurethane coating has the excellent comprehensive performance such as the good product performance, the low product price and environment friendliness, operability is high, and industrialized production is facilitated.