Abstract: The analysis method of limit equilibrium theory to the reliability of soil nail support is one by which stability coefficient is computed through searching potential sliding failure surface with ‘deterministic’ strength parameters of soil mass and soil nail. But the randomness of the calculating parameters and the constraint condition, which latter strength parameters may be no satisfaction, take reliability degree of stability analysis to reduce obviously. So the supporting reliability of soil nail is analyzed with Chance Constrained Programming (CCP), by which the base is the randomness of strength coefficients that was controlled by probability theory and the randomness of constraint condition that was satisfied by soil strength coefficients, and the determination of safety status to soil nail supporting wall are discussed. As an example, the safety analysis in the light of the theoretical idea is carried out in some engineering.