The invention discloses a toughened modified
flame-retardant
epoxy resin composition which is prepared by the following steps: S11, performing
thermal reaction on 50-90 parts by weight of
flame-retardant
epoxy resin, 5-20 parts by weight of an
epoxy diluent and 10-25 parts by weight of a
toughening agent under the action of 0.01-0.5 part by weight of a catalyst to prepare toughened modified
flame-retardant epoxy resin A; s12, heating and mixing 0-5 parts of an auxiliary agent, 10-40 parts of a flame retardant, 3-15 parts of a
pigment and the toughened modified flame-retardant epoxy resin A, and then adding a chain
extender for
thermal reaction copolymerization to obtain toughened modified flame-retardant epoxy resin B; s13, mixing 1-10 parts of a latent curing agent and 1-6 parts of an
accelerant with the
toughening modified flame-retardant epoxy resin B to prepare a
toughening modified flame-retardant epoxy resin composition; a
composite material product prepared from the toughened modified flame-retardant epoxy resin composition and a
fiber reinforcement can meet airworthiness standard requirements such as BMS8-2 Class3 Grade A TYPE 45 and the like, and is suitable for manufacturing of aircraft cargo hold wallboards.