Intercropping has the characteristics of being high efficient and environmental friendly. It might be an important part of the sustainable agriculture in the future. The present study reviewed the semi-empirical and theoretical models for estimating light interception of intercropped canopies, and then analyzed the mechanisms responsible for high yield of intercrops from the perspective of light utilization. Intercropping could increase light interception, or promote the efficiency of converting captured light, or change the harvest index of crop. For the intercrops with relative long co-growth period, yield advantage is mainly attained from the efficient light capture by the dominant crop and the efficient light use by the subordinate crop, while for the intercropping systems with shorter co-growth period, the increase of light interception by both crops is the primary drive force for the intercropping benefit.