With the continuous expansion of underground space development in both scale and depth, excavation engineering is facing unprecedented technical and environmental challenges. A comprehensive analysis of the response of pile-anchor support structures during excavation of foundation pits was conducted by combining laboratory model tests and numerical simulations. A staged excavation model test was conducted to simulate the excavation process under different working conditions, and a corresponding numerical model was established using the ABAQUS finite element analysis software. Key parameters, including the bending moment of the retaining piles, horizontal displacement at the pile head, and ground surface settlement outside the pit, were monitored to investigate their variation patterns under different conditions. The results indicate that the bending moment of the piles increases with the depth of excavation, while the application of anchor prestress effectively reduces the bending moment in the prestressed zone. The ground surface settlement exhibits a "spoon-shaped" distribution, and the prestressed anchors significantly reduce the settlement values. The displacement at the pile head increases with the excavation depth, and the application of prestressed anchors also reduces the displacement. The research results provide a certain scientific basis for the design and optimization of pile-anchor support systems in deep excavation projects.