The computed tomography technique is employed to reconstruct the structure of Ni foam, and the Monte Carlo method in combination with the octree algorithm to model the pore-scale radiative transfer of Ni foam. The accelerating effect of the octree algorithm on the radiative transfer is analyzed. The results indicate that the maximum relative error of the calculation value of radiative property between with and without the octree algorithm is less than 1‰. Within the range of optimal spatial depth, the larger the spatial depth and the more the model element is, the more obvious the accelerating effect in computation is.