Molten Al-Si alloy phase change material would produce a certain corrosion to the heat exchange tube in solar thermal power generation integration system. C1, C2 and C3 protective coatings were prepared to enhance the life of 20G heat exchange tube. The properties of thermal shock resistance, adhesion and anti-corrosion of coatings were also studied. Results show that three coatings have good thermal shock resistant and adhesion properties, and C3 coating has the best capability of anti-corrosion after 1080h corrosion test. Compared with 20G steel substrate, the thickness of corrosion layer of 20G steel sprayed C3 coating drops 93.69%.