The invention discloses a preparation method of a sprayed surface layer of an environment-friendly polyurethane plastic track. The method comprises the steps of preparing a component A: adding polyether polyol into a reaction kettle, stirring and heating to 80-160 DEG C, dehydrating, cooling to 40-50 DEG C, adding isocyanate, stirring, and performing constant-temperature reaction at 80-85 DEG C for 2-4 hours; preparing a component B: uniformly mixing polyether polyol, a chain extender, a plasticizer, an ultraviolet light absorber anti-mildew agent, a thixotropic agent, a silane coupling agent and filler, shearing at a high speed, milling, and performing vacuum heating at 60-70 DEG C for 1-3 hours; mixing the component A and component B at a mass ratio of 1:(3-5.5); adding an inert amine dryer; stirring uniformly and spraying on the bottom layer of the polyurethane track. By adopting the method disclosed by the invention, the specific pungent smell of a conventional polyurethane track is avoided, the foaming effect is reduced, the usability of the track is improved, and the service life of the track is prolonged.