This paper, based on the reinforcement project of anti-slide piles at Shenjiabao on the south side of Wangjiayan in Beichuan, systematically investigates the dynamic response patterns of slope reinforcement with anti-slide piles under strong seismic action through on-site low-strain testing, concrete strength testing, FLAC3D numerical simulation, and pseudo-static theoretical calculations. The results indicate: (1) Low-strain reflection wave detection shows the piles are intact, and numerical simulation verifies that the anti-slide piles did not fail under the Wenchuan earthquake (peak acceleration of 1.0g); (2) The slope's dynamic response characteristics are significant, with the peak ground acceleration (PGA) amplification factors along the slope surface and vertical measurement lines increasing with slope height, but the anti-slide piles can inhibit the PGA amplification effect. The maximum horizontal displacement at the toe of the unsupported slope reached 0.97 m, which was reduced by 89% after reinforcement; (3) The internal force distribution characteristics of the anti-slide piles show that the peak shear force and bending moment of the pile are located near the sliding surface, and the pile top displacement9.78 cm under seismic action meets the allowable limit specified by the code; (4) Parameter sensitivity analysis shows that a pile length of 16 m and a spacing of 6.75 m are the optimal seismic design parameters; (5) The pseudo-static method and numerical simulation results are consistent in trend, but the former calculates the pile's shear force and bending moment to be 2.93% and 5.87% lower, respectively, suggesting a safety factor of more than 1.2 for seismic design. The study reveals the dynamic response mechanism of anti-slide piles under strong seismic action, providing theoretical and technical support for seismic design of slopes in high-intensity areas.