Preparation method of self-extinction waterborne polyurethane dispersoid

The invention discloses a preparation method of a self-extinction waterborne polyurethane dispersoid, and belongs to the technical field of high polymer materials, wherein the preparation method comprises the steps: in parts by mole, mixing 0.04-0.3 part of dihydric alcohol, 0.5-1.6 parts of a crystalline compound and 1.3-2.7 parts of an amorphous compound for reaction, and then adding 2.1-5.3 parts of polyisocyanate; and adding a solvent and 0.04-0.36 part of a hydrophilic chain extender after the reaction, and adding a neutralizer after the reaction to obtain the self-extinction waterborne polyurethane dispersoid. The self-extinction waterborne polyurethane dispersoid prepared by the preparation method is used and dried; a crystalline chain segment provides certain tensile strength for acoating layer, and an amorphous chain segment provides flexibility, so that the obtained coating layer has a uniformly distributed uneven surface, generates obvious scattering on incident light, greatly reduces the glossines