Abstract: Traditional reinforced-concrete anti-slide piles used for slope support involve high construction safety risks, long construction periods, and high costs. To address these limitations, this study proposes a new emergency slope-support system based on steel-pipe anti-slide piles and investigates its reinforcement mechanism under pile-soil interaction. A constitutive model for the pile-soil interface was developed, and finite-element numerical simulations were carried out to establish a physical-mechanical model representative of typical soil-rock strata in Gansu Province. The effects of soil-rock parameters, embedment depth, pile spacing, and arrangement pattern on the internal force and deformation of steel-pipe anti-slide piles were analyzed. The results indicate that, for single-row steel-pipe anti-slide piles in soil layers, flexural resistance is the primary controlling factor. The pile ends show negative displacement and can be treated as free ends, and the optimal embedment depth is greater than 2/5～1/2 of the pile length. In rock layers, shear resistance becomes the controlling factor, and the pile ends behave as simply supported or fixed ends; the optimal embedment depth exceeds 1/3～2/5 of the pile length. For double-row piles, as pile spacing increases, the maximum positive bending moment of the front-row piles decreases, whereas the maximum negative bending moment of the rear-row piles increases. Overall, the displacement-control performance of the pile-group system is superior to that of single-row piles. Portal-type double-row piles provide better control of the maximum positive and negative bending moments of the rear-row piles, whereas the pile-group system has a more significant control effect on the bending moments of the front-row piles. This study further reveals the internal-force redistribution mechanism and synergistic displacement evolution of steel-pipe anti-slide piles under pile-soil coupling and proposes a dual-control design criterion for displacement and bending moment based on failure-mode identification. The competition mechanism between the pile-group effect and the soil-arching effect induced by changes in pile spacing is also clarified. These findings provide a theoretical basis for optimized design and construction of steel-pipe anti-slide-pile retaining structures, particularly in emergency rescue projects.