A micro-scale W skeleton porous model was built by random Voronoi segments, and the infiltration process of CuW alloy was then simulated using a finite volume method based on the Navier-Stokes momentum equation modified by Young-Laplace. The simulation results show that improving the wettability of Cu-W can accelerate the velocity in the center of copper flow and strengthen the adhesion of liquid copper to the wall of W skeleton, resulting in the mechanical combination at the interface of Cu-W. Moreover, the transition of reaming and shrinkage due to the ununiform pore size can produce whirlpools of copper liquid in the pores, resulting in pores in the CuW alloy, and thus the filling rate of copper liquid is decreased.