Bottom-bearing steel pipe concrete inclined support technique is a promising method for foundation pit excavation. While its effectiveness is evident in various engineering cases, its underlying mechanism requires further investigation. This study establishes a numerical model using finite element simulation, validated against monitoring data from specific projects. It explores the deformation of the inclined support during excavation, revealing insights into its performance under different soil conditions and tilt angles. Findings indicate significant control over soil and support deformation, especially in soft soil areas. Increasing the tilt angle enhances lateral force resistance but raises project costs. Thus, selecting the appropriate angle is crucial based on specific project needs and soil conditions.