In order to research the displacement of the top of the anti-stide pile and surface deformation of the landslide,this paper introduces decision tree method to build three Decision-making plan branches including designer displacement of the anti-slide pile,the measured displacement,the failure probability of the andslide surface and the probability analysis model of decision tree including decision-making endpoints analyzed by failure probability of anti-slide pile. As a result.,a judgment method to analyze the reliability of anti-slide pile is found. Its specialties are using the deformation features of the top of the anti-slide plie combined with visible deformation phenomenon to estimate the reliability of anti-slide pile synthetically. And its result is more reasonable.