The work aims to improve rain erosion resistance and antistatic property by developing a new rain erosion resistant and antistatic coating system to meet the higher requirement for long-term salt fog resistance and hydrothermal resistance made by composite rain erosion resistant and antistatic coating system in high-salt and highly hygrothermal environment. The coating system was made based on a new polyurethane elastomer which was modified by saturated polyolefin resin. The coating formula was optimized by studying effects of amount of saturated polyolefin resin and electrical fillers on coating system properties. The system exhibited excellent properties. Mechanical strength was 21.3 MPa and elongation was 385% when mass fraction of saturated polyolefin reached 40%. After the system has been immersed in 80 ℃ hot water for 19 days, its mechanical strength was 15.8 MPa and elongation was 280%, which showed good water resistance. The surface resistance of antistatic coating was 4 MΩ/m2 when mass fraction of conductive powder was 16%. The electrical property remained stable after 75 days′ salt fog test. Meanwhile, the coating system exhibited excellent processing property, and could be cured at room temperature. The introduction of saturated polyolefin significantly improves mechanical strength and elasticity of the coating, and enhances its rain erosion resistance. The optimization of conductive filler promotes antistatic property of the coating system. Meanwhile, the new coating system has good processing properties and shows a broad application prospect.