The mixed radiation field and high-temprature environment in nuclear power plant required an overall performance for radiation shielding composite. This study aimed to develop a new type of epoxy resin-based radiation shielding composite which would tolerate high-temperature in n-γ mixed radiation field. The preparation of the composites was doped functional particals into the epoxy resin matrix, such as B4C,W,Mg(OH)2,glassfiber.The MCNP method was used to simulate the radiation shielding capability of different formulation of composite, as the primary reference data of material formula. The initial decomposition temperature of the prepared radiation shielding composite is 380 ℃. The test results of radiation shielding performance were consistent with the simulation calculation results. By adding the B4C particals, tungsten powder, glassfiber, the radiation shielding performance and mechanical properties of the composite were improved greatly, the neutron shielding performance was better than common materials such as high density polyethylene (HDPE),boron polyethylene,etc. Comprehensive experiments showed that the composite material had the advantages of heat-resistant and low density, it could be used in mixed radiation field.