Abstract: Micron-sized hydroxyl magnesium silicate powders were prepared with hydrothermal synthesis method. The optimum content of hydroxyl magnesium silicate in the preparation of hydroxyl magnesium silicate/silane composite films on cold-rolled steel sheets were explored. The corrosion resistance of the prepared silane composite films was analyzed by Tafel curves, alternating current (AC) impedance and CuSO₄ dropping. The surface topography of powder and silane composite films were characterized with scanning electron microscopy. The results show that the dense uniform of the hydroxyl magnesium silicate/silane composite silane film can be obtained when the concentration of hydroxyl magnesium silicate in the slurry is optimized to be 100 mg/L. The self-corrosion current density decreases from 2.603×10^-6 A/cm² of the silane film to 4.368×10^-7 A/cm² of the composite silane film, its corrosion resistance performance is improved.