Low level light treatment using red and blue light is considered as a novel and non-invasive therapy in a variety of diseases, such as Acne, when the area of therapy is larger than the area that one light source covers. As a result, understanding of the light distribution is needed. On the other hand, dose is also of importance. At present, doses of therapy rely on rough estimation and experience. For this reason, it is of great significance to accurately calculate absorption doses of low-level light /laser therapy for people with various of skin. In this study, we used 3-D voxelized Monte Carlo simulation tool MCVM to accurately calculate the distribution of absorbed photon energy on face of a digital human head model VCH, which is a dataset of adult Chinese male corpse slice images. By simulating the light propagation on three different area on face, which are chain, cheek, and forehead, we demonstrated the typical energy and flux distribution for all these areas. And we found that 0.68cm away from the light source, the absorption intensity is only 0.001 times comparing to the position directly under light source. And the absorption distribution along the depth direction is also shown. The typical distribution in horizontal and depth direction may be a good guidance for the understanding of light therapy in the aspect of dose estimation and light source design.