In order to establish a process of synthesizing high purity vaterite calcium carbonate with calcium chloride as raw material and storing CO₂, this paper used calcium chloride as calcium source, CO₂ carbonization method and vitamin C as crystal form regulator to control the synthesis of vaterite. The products were characterized by X-ray diffractometer, Fourier transform infrared spectrometer, scanning electron microscope, etc. The effects of different concentrations of vitamin C on calcium carbonate crystals and morphology were studied, and the possible formation mechanism of vaterite under the regulation of vitamin C was discussed. The results show that vitamin C has a significant effect on stabilizing the crystalline form of vaterite. When vitamin C is not added, the product is a mixture of vaterite and calcite, while vaterite with a purity of 100% can be obtained by adding 0.1% (mass fraction) vitamin C. Moreover, with the increase of vitamin C concentration, the specific surface area of calcium carbonate increases from 3.63 m²/g to 11.62 m²/g, and the crystal size decreases from 1~3 μm to 0.3~0.6 μm. This study provides a simple, green, and low-cost method to prepare pure vaterite while safely and effectively sequestering CO₂ greenhouse gases.