To meet the requirement of sustainable development for coatings industry，this article provided three low viscousity HDI hardener with different functionalities using in 2Kwaterborne polyurethane coatings and high solid polyurethane coatings. The drying speed， mechanical properties，pot-life，and appearance of the coatings were tested. The results indicated that low viscousity hardener could significantly reduce VOC emissions and exhibitedexcellent appearance and application performance in both high solid polyurethane coatings andwaterborne polyurethane systems.