Provided are crystalline form A of rebaudioside D, and a preparation method and application therefor. In X-ray powder diffraction analysis measured using Cu-Kα rays and with 2θ being expressed in degrees, crystalline form A of rebaudioside D has significant characteristic diffraction peaks at least at 4.53, 6.38, 12.76, 13.52, 17.48, 17.96, 20.07 and 22.63. The preparation method is a suspension method, a solvent evaporation method or a cooling method. The preparation method has a simple process, and is convenient to operate. A rebaudioside D crystalline form A product has a good degree of crystallinity, good water solubility, and high chemical stability.
