Abstract: Pile-anchor support System deep foundation design research involves pile technology, bolt technology,construction technology and monitoring techniques. Taking a deep foundation pit project as the research object and combined with the field monitoring data, this article studies the deformation characteristics of horizontal shift and ground settlement and the internal force change process of anchor cable in the course of excavation, obtain the regularity conditions of different excavation pile-anchor retaining structure deformation and cable force with the foundation pit. Anchor prestress loss mainly occurred in a short time after the cable locked, the prestress gradually restored with the increasing depth of excavation and the anchor has the maximum of force near the second floor of the anchor; The anchor head have a tiny outside lateral horizontal displacement after locked, then truning into inside lateral horizontal displacement with excavation,displacement increases with the excavation. Meanwhile,the use of prestressed cable,so that to effectively control displacement of the supporting piles are horizontal and vertical,thus control stability of the foundation better; the horizontal displacement does not necessarily occur in the top of pile, but within a certain range above the excavation surface.