Abstract: In the case of an internally supported pit adjacent to structures, an area of limited soil will be formed outside the pit, which will result in an asymmetric soil condition on both sides of the pit. Indoor model tests are used to analyse the main deformation and bearing capacity of the unilateral asymmetric pit with finite soils, and to investigate the mechanism of the overall push-back displacement of the supporting structure triggered by the asymmetric working condition. The test shows that the deformation of the asymmetric pit consists of two parts: that caused by excavation and that caused by the overall push-back displacement of the supporting structure. The overall pushback displacement of the support structure caused by asymmetry on both sides will lead to the increase of deformation on the semi-infinite side of the soil body, the decrease of soil pressure in the active zone, and the constraint of deformation of the support piles on the finite side. In the case of a large degree of asymmetry between the two sides of the pit, the excessive pushback displacement will cause the deformation of the finite side of the soil body towards the outside of the pit, and the deformation of the supporting piles will change significantly. In the case of a large degree of asymmetry, the soil pressure in the active zone of the finite side appears to change in shape and magnitude, and in the case of a smaller degree of asymmetry, only a change in magnitude occurs.Therefore, when the asymmetric condition of unilateral finite soil body occurs in the foundation pit, the influence of pushback displacement should be fully considered, so as to obtain a more reasonable design and construction scheme of foundation pit support.