In order to make high value-added use of calcium carbide slag and sequestered CO2, high purity spherical vaterite calcium carbonate was prepared by carbonation method using calcium carbide slag as raw material and glycine (Gly) as an additive and process of calcium carbide slag-CO2 reaction method under atmospheric pressure.The effects of Gly doping on the content of product vaterite and the stability of vaterite were investigated by scanning electron microscopy and powder X-ray diffraction and other analytical techniques, and the mechanism of vaterite formation and the recycling of Gly in filtrate were discussed. The results show that the content of vaterite tends to increase and then decrease with the increase of Gly doping. The prepared vaterite has good thermal stability. During the formation of vaterite, calcium carbonate is converted from calcite and small needle-like aragonite crystals by agglomeration, dissolution and precipitation to spherical vaterite with rough protrusions on the surface. Gly in the filtrate can be recycled to prepare vaterite without affecting the content of vaterite. The calcium carbide slag-CO2 reaction method is a simple, low-cost and less polluting new process for the preparation of vaterite.