The invention provides a wall surface aqueous environmentally-friendly coating material capable of being repeatedly written with water, and a preparation method thereof, wherein the coating material comprises, by mass, 20-70% of an aqueous coating material emulsion, 2-30% of a water-induced color developing material, 1-8% of a cosolvent, 5-35% of a filler, 0.5-5% of a film forming aid, 0.5-3% of adispersing agent, 0.01-1% of a defoamer, 0.01-1.5% of a leveling agent, 0.02-3% of a thickener, 0.03-3% of a preservative and the balance of water. According to the invention, the water-induced colordeveloping material is used as the aqueous coating material of the color developing agent, and has the properties of no color after being dried, color developing when meeting water, fading after being air-dried and dewatered, and color developing again by using water after being brushed on a wall surface, so that the repeated writing on the wall surface coated with the coating material of the invention can be achieved by using the water as the writing liquid; and the coating material can be used for manufacturing teaching, training and child scrawling boards, so that the teaching environmentis environmentally-friendly, sanitary and healthy.