Abstract: The whole stability analysis of the soil-nailing protection structure is the key checking computation item in the design of the soil-nailing protection, which affects directly normal work of the soil-nailing protection structure. Starting from the interaction between the soil-nailing and the soil body, applied soil plasticity theory and slope limit equilibrium analysis method, a new method was put forward for stability analysis of the soil-nailing protection structure based on the soil-arch effect and compared with current methods in the specification. The results show that the influence of the diameter and the spacing of the soil-nailing on stability of soil-nailing protection structure is much greater than that obtained from the method in the specification.