The invention belongs to the field of heat conducting composite materials, and in particular relates to a high thermal conductivity epoxy resin composite material as well as a preparation method and application thereof. The method comprises the steps of firstly, preparing an ethylenediamine crosslinked graphene oxide aerogel as a heat conduction network skeleton, and then using dopamine, 3-aminopropyltriethoxysilane, gamma-(methacryloxy)propyl trimethoxy silane or sodium dodecyl sulfonate to modify the aerogel; finally, pumping epoxy resin and a curing agent into the aerogel skeleton by meansof vacuum assisted suction filtration, and carrying out hot-pressing to obtain the composite material. The mass ratio of a cross-linking agent ethylene diamine capable of reacting with resin matrix tographene oxide is equal to (2 to 3)-(1 to 3). The heat conductivity coefficient of the high thermal conductivity epoxy resin composite material prepared by the method can reach 1.9-5W m<-1>K<-1> in the plane direction, and the heat conductivity coefficient of the vertical surface can reach 0.29-0.6W m<-1>.K<-1>; the composite material can be used for preparing products with multiple thicknesses and different thermal conductivities, and is suitable for mobile phones, tablet personal computers and various consumer electronics.