Anti-sliding piles are commonly implemented to reinforce landslides. Considering the complex nature of this medium, there is substantial spatial variability in the mechanical parameters of rock and soil masses. However, the influence of spatial variability on the anti-sliding pile remains unclear. In this study, the Erdaogou landslide is taken as a case study in terms of the random response of anti-sliding piles considering spatial variability. Based on comprehensive on-site investigations, various numerical calculations were conducted for the comparative analysis, involving stability analysis and the reliability evaluation of the Erdaogou landslide. The results show that treating mechanical parameters of sliding masses as random variables could result in the probability of overestimating landslide failure, leading to the squandering of supporting materials. Specifically, the coefficient of variation has the greatest influence on failure probability, and the vertical scale of fluctuation showed a larger impact on reliability than that of the horizontal scale of fluctuation. As for the rotation anisotropy, the failure probability fluctuated with the increase in the rotation angle. Taking spatial variability into account, pile top displacements and maximum bending moments tower above those obtained via stability analysis. The related studying methods could provide guidance for the optimal design of anti-sliding piles and the threat control of landslides.