Abstract: Due to the different thickness, the silty and peaty soil layer can have a significant impact on surface settlement and deformation of the supporting structure. The different insertion ratios of soldier piles can also affect the stability and safety of the excavation. Therefore, to understand the influence of the thickness of the silty and peaty soil layer and the insertion ratio of the soldier piles on the horizontal deformation and surface settlement of the supporting structure, a numerical model was established for the analysis and compared with the measured results. The research results showed that the maximum horizontal deformation of the supporting structure increased with the increase of the thickness of the silty and peaty layer, and the maximum deformation of the supporting structure reached 41.3 mm when the thickness of the silty and peaty soil layer was 20 meters; The horizontal deformation of the supporting structure under each thickness of the silty and peaty soil layer shows a trend of first increasing and then decreasing with the increase of depth. The larger the thickness of the silt layer, the more obvious the trend of deformation increasing or decreasing; The amount of surface settlement increases with the thickness of the silty and peaty soil layer, reaching a maximum of 31.33 mm when the thickness of the silty and peaty soil layer is 20 meters; The horizontal deformation value of the supporting structure gradually decreases with the increase of insertion ratio; When the insertion ratio is below 0.51, reducing the insertion ratio will greatly increase the horizontal deformation value of the enclosure structure; When the insertion ratio does not exceed 0.511, the increase in the maximum settlement gradually becomes apparent. The maximum surface settlement increased by 15.08 mm when the insertion ratio decreased from 0.384 to 0.256, with an increase of nearly 28.6%.