The heat dissipation performance of the epoxy molding compound(EMC) is very important for high power application. In this paper, the thermal transport properties of thermoset epoxy(EP) based EMC containing silica particles(SiO₂Ps) and diamond particles(CPs) were calculated using two different scale approaches. Firstly, the representative volume element(RVE) of EMC was modeled using molecular dynamics(MD) to calculate the effective thermal conductivity(ETC). The crosslinking of EP between Diglycidyl Ether of Bisphenol A(DGEBA) resin and JEFFAMINE® D-230 hardener was modeled. The results indicate that the CPs can increase the ETC of composite by 71.4 % than that of SiO₂Ps. The interfacial thermal conductance(ITC) of Silica/EP interface was 1.33 times higher than that of Diamond/EP interface. The discontinuous temperature gradients on interface was observed in the RVE filled with dispersed fillers. In addition, a macroscale approach was used to determine the ETC of the EMC using finite element method(FEM) and the Maxwell theoretical model. The effects of fillers' shape and the ITC of fillers/EP interface on the ETC of EMC were analyzed. With the increase of the ITC, the ETC of the composite increases gradually. When the ITC exceeded a critical value, the ETC did not change. The chain fillers were more conducive to heat transport. The results of the two multiscale modeling techniques were well consistent.