Heat conduction process in fractal structure is analyzed through numerical computation method in this paper. Fractal structure can be simplified as a kind of binary mixture, composed of pore and matrix. If convection and radiation heat transfer are neglected, it is found that the effective thermal conductivity for random Sierpinski Carpet is approximately scaled as the structure length scale or matrix percent. The macro-pore distribution and fractal dimension have much effect to the effective thermal conductivity. That is to say, the structure heterogeneity plays an important role in heat transfer process for fractals. The research would be helpful to understand the micro-scale heat conduction mechanism well.