This paper develops a 3D stochastic model to describe porous metal fiber sintered sheet (PMFSS), which is a nonwoven fiber mat composed of curved and partial overlapped sintered fibers. Firstly, single fibers of PMFSS are modeled based on morphology information involving curvature and orientation extracted from the actual structure employing the 3D micro-CT imaging. Secondly, since fibers are partially overlapped at sintered joints (fiber to fiber overlapping section) during sheet formation process, a graphics processing unit (GPU) accelerated force biased simulation is introduced, which turns the arbitrarily overlapped single fibers into partially overlapped ones, for the sake of making the virtual geometry more realistic. Finally, fibrous geometries resembling the microstructure of PMFSS with various porosities are established and further imported into the STAR-CCM + CFD package (CD-adapco, London) to study the effective thermal conductivity. Results illustrate that the numerical effective thermal conductivity of PMFSS agrees well with the experimental results in the in-plane direction. Besides, the sensitiveness of effective thermal conductivity due to structural anisotropy is also verified. (C) 2017 Elsevier B.V. All rights reserved.