The uncertainty problem of geotechnical engineering is one of the research hotspots in recent years. The slope reliability analysis is a foundation.According to the principle of unscented transformation,the analysis methods and implementation steps of slope reliability are given.Based on the existing examples of the homogeneous slope and the layered slope, the rationality and applicability of slope reliability analysis method based on unscented transformation are discussed. The results show that the reliability analysis of slope based on the unscented transformation does not depend on the distribution types of variables,and this method is convenient in application and efficient in calculation. When the slope with higher reliabilityis analyzed,a large relative error is caused because the value of failure probability is small.Therefore, the method should be chosen carefully.But for the slope with lower reliability (higher failure probability,P_f>7%) is more concerned in the engineering,the method of slope reliability analysis has better applicability than the Monte Carlo method. Mean while,the relative error of this method is approximately within 5% and the error fluctuation caused by the change of variable correlation coefficient is small.