The pile-anchor supporting structure system is a supporting method which combines slope protection piles with soil anchor bolts. It is widely used in slope and deep foundation pit support due to its safety and economic characteristics. However, its application in ultra-deep foundation pits is still under exploration. According to the engineering geological conditions and hydrogeological conditions at the foundation pit of Fengcheng International Trade Project, taking into account of its surrounding conditions, and with comparison of several different foundation pit support plans, the pile-anchor supporting system was selected, which is technically feasible, economically reasonable, provides good overall performance and is convenient for the excavation of foundation pits and subsequent construction. Then the soil pressure calculation, cast-in-place pile design, anchor bolt design and stability checking calculation were carried out for the foundation pit supporting structure. Later deformation monitoring verified that the pile-anchor support was safe, economical and feasible for the ultra-deep foundation pit.