Satellite Based Augmentation System is an important part of BDS satellite navigation system. First of all, the basic composition of Beidou System Satellite Based Augmentation System (BDS SBAS) is introduced. Then, the complete and correlation algorithm is introduced. Finally, the experiment of positioning accuracy of BDS SBAS using anti-interference antenna which with and without interference is done. The result shows that the positioning accuracy of BDS SBAS is obviously better than positioning.