The disclosure belongs to the technical field of food additives, and provides a method for preparing a calcium carbonate-based edible lake. The method comprises the following steps: S1, dissolving carbonate in water to obtain carbonate solution; S2, dissolving water-soluble anionic pigment into the carbonate solution obtained in step S1 to obtain mixed solution; S3, adding hydrochloric acid to the mixed solution obtained in step S2 to adjust pH to 7-10.5; S4, dissolving a calcium salt into water and then adding the above solution into the solution obtained in step S3, controlling the pH of the mixed solution to 6-9, carrying out ultrasound treatment for 1-10 min, centrifuging to obtain a calcium carbonate precipitate adsorbed with pigment; and S5, drying and grinding the calcium carbonate precipitate adsorbed with pigment obtained in step S4 to obtain the calcium carbonate-based edible lake.