Abstract: It is incontestable that the Surveying Robot (automatic electronic Total-station) can monitor dam deformation automatically, but the stability of the base point below Surveying Robot exerts tremendous influence on precision. The Surveying Robot can not monitor the deformation point while the surveying line is obstructed. To overcome the problem, based on double basis stations GPS technique, the automatic monitoring system of dam deformation was developed, which reduced the influence of base point stability, simplified the monitoring procedures and cut down the fixed investment. This paper introduced its structure and work principle and a monitoring case was presented.