In order to save as much as possible of deep space optical network node energy, directional flood routing algorithm (DFRA), the algorithm is based on deep space optical communication is sensitive to angle and azimuth of features, based on the deep space node model of the interface, will air separation combination of reuse and frequency division multiplexing, supports the transfer of multiple hops routing orientation, in the process of the routing path finding only part of the nodes involved. The simulation results show that, compared with the traditional flood routing algorithm(TFRA), DFRA can avoid the non-directionality and blindness problems existing in TFRA, and is more energy efficient, and the performance of network transmission delay and delay jitter is better than TFRA.