Preparation method of medium-temperature cured high-Tg low-bromine epoxy resin prepreg

The invention discloses a preparation method of a medium-temperature cured high-Tg low-bromine epoxy resin prepreg. The epoxy resin prepreg is formed by mixing a component A, a component B and a component C into glue and then coating the glue on glass fiber cloth to be cured at medium temperature, and the component A is a high-Tg low-bromine epoxy resin mixture modified by a modified coupling agent; the component B is a curing component solution containing an aromatic acid modification accelerant; and the component C is a composite filler reinforcement. Through surface modification of the high-Tg low-bromine epoxy resin by the modified coupling agent, chemical modification and intervention of the curing accelerator and dispersion pretreatment of the composite filler, the compatibility of the high-Tg low-bromine epoxy resin with the curing agent and the composite filler is greatly improved; the epoxy group and the curing agent with the active functional group are easily subjected to cross-linking reaction to f