An analytical model for the reliability of the embedded depth of rigid anti-slide pile was established by introducing the bi-parameter approach used in the computation of lateral loaded pile. A reliability index target was determined by searching for the minimum of reliability index at a specified embedded depth incorporating with stochastic optimization algorithm, and was used to guide the design for the embedded depth of rigid anti-slide pile. Practical case study demonstrated that it was more economical to determine the embedded depth in the bi-parameter approach than in traditional ground coefficient methods. Analysis of the parametric sensitivity indicated that the determination of the embedded depth of the rigid anti-slide pile was more sensitive to the unit weight, internal frictional angle and cohesion of sliding mass than to the gravity of the embedded length and the proportional coefficient of ground coefficient. It is suggested that more concern be given to the variation of the former three parameters when conducting the embedded depth design of rigid anti-slide pile.