The present invention relates to a new crystalline form of dapagliflozin represented by formula (I). The crystalline form has a characteristic absorption peak at about 4.318 (20.45) in an X-ray powder diffraction pattern shown by angle 2 theta and interplanar spacing (value d). It can be prepared by dissolving dapagliflozin in good organic solvents, adding poor solvents, stirring to crystallization, filtering and drying. The new crystalline form of dapagliflozin of the present invention has the following superior features: good solubility, low hygroscopicity, high stability and good preparation reproducibility.