As raw materials, polyurea resin (PU) and hexadecyltrimethoxysilane (HDTMS) were diluted with ethanol, then PU paints with concentrations of 3% to 100%, and HDTMS paints with concentrations of 1% to 30% were prepared respectively, of which the contact angles for water were comparatively examined. Meanwhile, a composite paint of PU-HDTMS based on the optimal concentrations of the above two paints was prepared. Further, coatings of PU, HDTMS and PU-HDTMS were applied on mortar blocks respectively. The anti-icing performance of the coatings was comprehensively evaluated by measuring the static freezing time on the coatings, the amount of ice accumulation on the coatings at various tilt angles, and the bond strength between the formed ice and the coatings at -20 ℃. The anti-icing durability of the coatings was assessed through multiple icing-deicing circles. The results indicated that the optimal concentrations for PU and HDTMS coatings were 7% and 5%, respectively. The surface of the 100%PU coating was smooth and exhibited low ice bond strength; however, its effectiveness in delaying freezing time was not significant, and the icing resistance of PU coatings decreased upon dilution. In contrast, the 5%HDTMS coating effectively delayed the freezing time while also demonstrating low ice bond strength. The contact angle of the PU-HDTMS coating was measured as 153.38°, which was superior to that of both the PU and HDTMS coatings.