Monitoring and early warning indicator system is set up based on actual condition of a certain rock slope and the method of constructing the warning indicator system. Considering the uncertainty of indicators were uncertainty, the analytic hierarchy process (AHP) method which is relatively subjective, and the information entropy method which is objective, are applied to calculate the weights for the slope monitoring and early warning system. Also, the unascertained mathematics theory is utilized to compute the uncertain weight information of the factor and indicator layers. Ultimately, the credibility of slope stability is about 92%. The calculated results are consistent with those of slope safty monitoring. Therefore, this comprehensive evaluation method of slope monitoring-warning introduced is scientific and reliable.