The effects of low harm deicing salt on the salt frost scaling of concrete surface, the ice formation pressure of salt solution, the degree of saturation in concrete and the bond strength between concrete and ice were investigated. The results show that the salt scaling of concrete is significantly reduced by the low harm deicing salt with the additive. Comparing with the 400% NaCl solution, the additive has no significant effect on the ice formation pressure of the salt solution, but significantly reduce the bond strength between the concrete and ice, and the degree of saturation in the concrete decreases. The improving mechanism of the low harm deicing salt on the salt frost scaling of concrete is well explained based on these measured data.