The analysis and solution of common problems in the preparation process of 2K waterborne PU topcoat with high gloss and high performance were introduced from formulation and application.The factors affecting appearance and performance of coating were overviewed,including selection of hydroxypolypolyols with isocyanate polymers,selection of various additives,pH value of the system and the ratio of NCO/OH in formulation,application condition and method as well as dry conditions.It provides some suggestions and references for 2K waterborne PU topcoat with high gloss and excellent performance.