The invention relates to lensing spherical vaterite calcium carbonate crystals with high purity and a preparation method thereof. The calcium carbonate crystals are formed into a lensing structure with a diameter of 0.8 to 3.0 mu m and a thickness of 0.5 to 2.5 mu m through aggregation of nanosphere particles with a size of 50 to 150 nm, and the content of spherical vaterite calcium carbonate is 100%. The preparation method comprises the steps of dissolving ionic liquid surfactants into deionized water, sequentially adding the aqueous solution of sodium carbonate and the aqueous solution of calcium chloride, carrying out stirring fro even mixing, and carrying out aging, separating and air drying; therefore, monodisperse lensing spherical vaterite calcium carbonate is obtained. The preparation method provided in the invention is simple; reaction conditions are mild and easy to control; the yield of lensing spherical vaterite calcium carbonate crystals is high; therefore, the preparation method is suitable for large scale production. The calcium carbonate crystals obtained in the invention have good monodispersion and uniform distribution and can be used as fillers in the industriesof papermaking and the like.