Abstract: Waterborne polyurethane is widely used in many fields because of its safety, non-toxic, excellent physical properties and chemical corrosion resistance. However, due to its easy combustion, its application scope is greatly reduced, so it is urgent to carry out flame retardant modification. This paper describes the classification and development status of waterborne polyurethane, introduces the common intrinsic flame retardants and composite flame retardants, and focuses on the examples of flame retardant effect, flame retardant mechanism, advantages and disadvantages of these two kinds of flame retardants on waterborne polyurethane. Finally, the modification direction of fire-retardant waterborne polyurethane is prospected and the defects of the waterborne polyurethane are provided.