The method of planetary ball mill was applied to produce granular-cold-water-soluble maize starch. Based on the single-factor test, the technical conditions of the ball mill were optimized through Box-Benhnken center composite design and response surface methodology. The properties of granular-cold-water-soluble maize starch were analyzed using polarization microscopy, scanning electronic microscopy and X-ray diffraction. The results showed that the optimum technical conditions are that the milling time is 3.24h, the rotating speed is 555r/min and the ratio of ball to material is 6.52∶1. At the optimum conditions, the average cold water solubility of granular-cold-water-soluble maize starch is 57.95%. The granular morphology of granular-cold-water-soluble maize starches became coarse instead of smooth and Maltese crosses were disappeared, the crystalline structure of granular-cold-water-soluble maize starches were changed from polycrystalline granules to non-crystalline granules gradually, the turbidity of granular-cold-water-soluble maize starch decreased. 