In accordance with high-risk condition of large-scale lifting equipment installation，Considering the installation license , installation management, installation technology,Establish two indicators evaluation of large-scale lifting equipment to install security system，Asked the catastrophe evaluation method to the analysis of large lifting equipment installed security situation.This method avoids the subjectivity of the underlying index weights determined,Use different mutation model normalization formula to calculate，Eventually come to the security situation of total mutations membership values，Evaluation of the security situation，Example shows that the method is reasonable and feasible.