Solid content is an important index of water based polyurethane. The high and low solid content not only affects the film formation rate of waterborne polyurethane in the drying process, but also affects the storage and transportation cost of polyurethane dispersion.At present, limited to the types of raw materials, preparation methods, complete sets of equipment and other conditions, the majority of domestic waterborne polyurethane is anion carboxyl as the hydrophilic group of waterborne polyurethane, the solid content is relatively low, mostly concentrated in 20-40%, its solid content is difficult to reach more than 50%, more difficult to meet the needs of market diversification.Therefore, the production of high solid content products (solid mass fraction above 50%) has a very positive and practical significance, can promote the wide application of waterborne polyurethane, become the development direction and research focus of water based polyurethane dispersion