Environment-friendly flame-retardant polyurethane emulsion and preparation method thereof

The invention discloses an environment-friendly flame-retardant polyurethane emulsion and a preparation method thereof, wherein the environment-friendly flame-retardant polyurethane emulsion is composed of the following raw materials in parts by weight: 26-38 parts of diisocyanate, 40-50 parts of macromolecular polyatomic alcohol, 2.5-10 parts of a flame retardant, 4-8 parts of an hydrophilic chain extender, 3-10 parts of a micromolecular chain extender, 1.5-9 parts of a neutralizer, and 0.5-1.5 parts of a catalyst. According to the invention, a chemical structure with a flame-retardant function is introduced onto a main chain of polyurethane, so aqueous polyurethane has the flame-retardant performance and the application range of the aqueous polyurethane is enlarged; and in addition, gradually increased requirements on the flame-retardant performance in the furniture industry and the construction industry are satisfied.