Abstract: Goaf disaster is one of frequently-occurred mining disasters.The uncertainty measurement theory is used to evaluate the risk of goaf.Considering that the factor value for affecting the stability of the goaf are easily grasped and of significance，13 factors of goaf risks are regarded as the discriminant index by comprehensive analysis，including rock structure，geological structure，intensity of surrounding rocks，hydrological condition，goaf shape，ore-body dip，high-span ratio，goaf volume，burial depth，maximum exposure area，exposure time，mining disturbances，and the condition of the neighboring goaf.The measurement function of each evaluation index is established based on the hazard degree of underground goaf and evaluation indexes' grading standards，and combining with the mechanism of underground goaf instability and some relevant research results as well.Then，the index weights and the comprehensive measurement of multiple indicators are calculated by using the information entropy theory.The hazard degree of underground goaf can be judged by credible recognition rule.This method is used to make evaluation on hazard of 12 underground goafs in a certain metal mine.The results show that the discrimination conclusion by this method is similar to the conclusion by the fuzzy comprehensive evaluation method and the matter-element analysis method，proving that the method is reliable and practical and can be applied and promoted to the actual engineering.

Key words: Goaf hazard, Unascertained measurement, Underground goaf, Stability, Entropy weight