the present invention provides a flame - retardant hardener for epoxy resin having a compound represented by formula : in addition , the present invention also provides a flame - retardant resin material comprising the aforementioned flame - retardant hardener for epoxy resin . moreover , the present invention further provides a method for manufacturing a flame - retardant hardener for epoxy resin , which can be directly applied in a resin curing process after a cooling step without additional purification . as described by the present invention , the flame - retardant hardener for epoxy resin in accordance with the present invention can replace the conventional toxic halogenated resins , and provide an environmental - friendly flame - retardant hardener for epoxy resin .