Abstract: With isophorone diisocyanate (IPDI), polybutylene adipate diol (PBA), dimethylolbutyric acid (DMBA) and butanediol (BDO) as the main raw materials, and in the case of not adding any oily solvent, the solvent-free high solid content waterborne polyurethane was synthesized, and the structure and properties of the solvent-free waterborne polyurethane emulsion and film were investigated. The results show that the viscosity of the solvent-free waterborne polyurethane emulsion increased with the increase of solid contents. The crystallinity of the polyurethane film increased with the increase of soft segment molecular weight and decreased with the increase of R value (the number ratio of NCO and OH). The tensile properties of the polyurethane film decreased slightly with the increase of solid contents.