Phosphorus-containing reaction-type fire retardant as well as synthesis method and application thereof

The invention belongs to the technical field of organic chemical engineering, and particularly relates to a phosphorus-containing reaction-type fire retardant as well as a synthesis method and application thereof. The chemical name of the fire retardant is bis-9,10-dihydro-9-oxa-10-phosphonia-10-phenanthrene oxide-base (diDOPO-MDCA), the compound has two hydroxyl active sites and can be used as the fire retardant for resin reacting with the compound, the element phosphorus is introduced into a molecular structure of a macromolecular material in a form of a covalent bond, the fire resistance of the resin can be improved, and a non-toxic high-efficiency long fire retardant purpose can be realized. The production condition is simple, the product purity and yield are relatively high, and the after-treatment process is simple.