The invention relates to a high temperature resistant epoxy pouring sealant, a preparation method and application thereof as packaging material in an IGBT (insulated gate bipolar transistor) module. The pouring sealant comprises a main agent A and a curing agent B, the main agent A is composed of polyfunctional mixed type epoxy resin, bismaleimide resin, an active diluent, an active toughening agent, inorganic filler, and a dispersant, etc.; and the curing agent B is mainly composed of an anhydride curing agent, inorganic filler, an accelerant, and a dispersing agent, etc. The preparation method consists of: firstly preheating the polyfunctional mixed type epoxy resin, then adding bismaleimide resin and performing low-speed stirring for cooling, then adding the active diluents and other components in order, carrying out high-speed stirring dispersion, and then conducting grinding and vacuum defoamation so as to obtain the main agent A; adding the anhydride curing agent, the inorganic filler, the accelerant, and the dispersing agent into a stirring kettle in order, and carrying out grinding and defoaming treatment, thus obtaining the curing agent B. The pouring sealant can be applied as a packaging material in the IGBT module, and has the advantages of good high temperature resistance, excellent electrical properties, good fluidity and mechanical properties, etc.