<p>In this study, the stability of an excavation reinforced by a composite soil nail wall system was analyzed using the kinematic method of limit analysis and the strength reduction technique. The stability analysis method proposed in this study is based on a novel failure mechanism for evaluating the safety factor and searching for the failure surface. This failure mechanism incorporated an innovative interaction zone to characterize the interaction relationship between soil nails and the surrounding soil. The stability analysis method proposed in this study incorporated various parameters associated with excavation and soil nails, thereby improving the accuracy and practical relevance of the obtained results. Compared to the finite element limit analysis method, the proposed method demonstrated higher efficiency and faster computation while achieving a lower safety factor and more accurate representation of the failure surface. Furthermore, the method exhibited strong sensitivity to excavation failure and was capable of effectively predicting associated failure risks. Finally, a parameter sensitivity analysis was conducted on this method to examine the effects of soil nail length, inclination angle, and the number of soil nails on the safety factor and failure surface.</p>