In cold regions the hydraulic concrete is undergoing the damage from the freezing-thawing cycles so in this paper the protection of organo-silicone coating for hydraulic concrete structures is researched. The rusults show that the organo-silicone can penetrate to 4-11mm inside concrete for the different concrete. The hydrophobic layer is formed between polar group of organo-silicone and the hydroxyl group inside the concrete. The wetting angle is larger than 90° between the harmful medium and concrete, which effectively prevents the invasion of harmful substances. By single salt freezing method the organo-silicone coating can decrease the scaled mass and the dynamic modulus of elasticity loss rate. It increases the freezing- thawing cycles resistance of the concrete in cold regions.