A method to determine the direction angle for bionic navigation is proposed. In order to do it, observation models of polarized light were obtained through full-sky imaging polarimetry, and the symmetry line （ solar meridian） was detected firstly; then the angle between solar meridian and the system moving direction was derived from simultaneous model, and the relative position of the sun was calculated by astronomical knowledge ; finally, the direction angle for bionic navigation was evaluated by utilizing sun azimuth to revise the angle between solar meridian and the system moving direction. This study improves previous conception with the changing solar meridian as a reference direction （0°） and provides a theoretic foundation for polarized light to be applied into navigation.
