【Objective】To study the variation laws of horizontal displacement of foundation pit retaining piles and surface settlement outside the pit under limited soil conditions.【Methods】This article conducted excavation model tests on a foundation pit with semi infinite soil on one side and finite soil on the other three sides.【Results】We obtained the variation laws of internal force, deformation, and surface settlement of retaining piles under excavation of finite soil foundation pits, and further analyzed the relationship between the horizontal displacement of retaining piles and surface settlement in finite soil foundation pits.【Conclusion】The results show that the horizontal displacement of the retaining pile body is positively correlated with the soil width B, and the reduction of soil width can effectively reduce the horizontal displacement of the retaining pile top and body; The maximum value of surface settlement increases first and then decreases with the increase of soil width B. In the case of limited soil width, soil width has a significant impact on surface settlement outside the foundation pit, and there is a critical value for soil width B; The maximum bending moment of the retaining pile body is positively correlated with the width B of the soil, and the width of the soil has little effect on the position of the maximum bending moment; The ratio of the maximum surface settlement outside the finite soil foundation pit to the maximum lateral displacement of the retaining structure, δ vm/δ hm, is between 0.9 and 1.85 and shows a decreasing trend with the increase of B. Among them, the δ vm/δ hm on the finite soil side of the foundation pit is greater than 1. Therefore, when designing and constructing finite soil foundation pits, more consideration should be given to the surface settlement outside the pit.