The invention discloses a preparation method of an ardealite-based self-leveling material and belongs to the technical field of building materials. The method comprises the steps as follows: firstly,crushing and sieving ardealite to obtain primarily refined ardealite, then, mixing the primarily refined ardealite with water, performing freezing and thawing circulation to prepare gypsum slurry, diluting the gypsum slurry with water, then, uniformly stirring and mixing the diluted gypsum slurry in graphene oxide, absolute ethyl alcohol and oleic acid, and performing freeze pressing, thawing anddrying to obtain a dried pressed material; uniformly stirring and mixing the dried pressed material with absolute ethyl alcohol, dropwise adding concentrated sulfuric acid, adding a calcium salt solution after a constant-temperature stirring reaction, adjusting the pH to be alkaline, and performing filtration, washing and drying after a hydrothermal stirring reaction to obtain modified ardealite;stirring and mixing the modified ardealite with anhydrite, semi-hydrated gypsum, cement, quartz sand, a gypsum retarder and a water reducing agent, and performing discharging and packaging to obtain the ardealite-based self-leveling material. The obtained ardealite-based self-leveling material has excellent flowing property and strength.