The-NCO/OH two-component polyurethane coatings were generally prepared by the reaction of NCO containing isocyanates and hydroxyl-terminated polyester resins.The isocyanate curing agents are expensive,and a large amount of volatiles are generated during the curing process,so it has a greater impact on health,and at the same time cause a certain degree of environmental damage.By reducing the hydroxyl content in the hydroxyl-terminated resin,the amount of isocyanate curing agent can be reduced,thereby saving costs,meeting environmentally-friendly coatings.The preparation methods of hydroxyl-terminated polyester resin for polyurethane coatings from the aspects of alcohols,acids,hydroxyl value,viscosity and additives were explored.The results showed that the polyurethane powder coatings with excellent leveling and mechanical performance was obtained by adding appropriate amounts of pigments and additives and the ultra-low hydroxyl value polyester resin with hydroxyl value of 24 mgKOH/g.Among then,the feeding quantity was 40 kg,the alkyd ratio was 1.077,the amount of TMP was 0.65 kg,EG was 3.0 kg,IPA was 0.5 kg,ADA was1.5 kg,and added with alkyd such as PTA and NPG.