Abstract: By designing a new type of flame retardant tackifier, DHQEP/ET3228, the flame retardant fiber reinforced epoxy composite was successfully fabricated via RTM process. DHQEP with epoxy functional group was synthesized to design the reactive flame retardant tackifier, which showed excellent flame retardancy(the LOI value reached to 36.8%) and retained the controllability of the preform dimensions(the springback angle was 1.24°). Meanwhile, the flame retardant tackifier would take part in the curing process and showed excellent compatibility with epoxy resin. Therefore, the interlaminar shear strength of the flame retardant fiber reinforced epoxy resin composite could also be maintained.