The invention relates to road marking coatings, in particular to an environment-friendly water-based road marking coating and a preparation method thereof. The coating is prepared from a component A and a component B. The environment-friendly water-based road marking coating has excellent wear resistance, weather resistance, stain resistance and adhesive force, has excellent binding capacity with a concrete pavement and can prevent a paint film from corrosion and exfoliation caused by efflorescence of the concrete pavement, thereby being capable of being widely applied to road surfaces such as airport aprons, indoor and outdoor large parking lots and the like adopting a cement matrix as a main material.