Abstract: In the light of external corrosion of oil tanks in Yonghui Tank Farm of Qinhuangdao, an coating painting system to solve corrosion problem is developed. With this system, coating painting to corroded external surface of oil tank can easily conduct. The coating painting procedure is that the quick-dying epoxy rich zinc is taken as primer, thickening epoxy coating as an intermediate coating (painting twice time)and the bicomponent polyurethane coating material as face coating. This combination coating material has been used in the corroded tanks. The quality inspection on this coating with two-year-service is made. The results show that the coating is perfect with a smooth surface and original thickness, which is suitable for the oil tanks located at coastal zone.