To make high valued use of calcium carbide slag and to sequester 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. The process of calcium carbide slag-CO₂ reaction was 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 X-ray diffraction， 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 for the preparation of 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.