The　rough　set　and　the　Monte-Carlo　index　score　method　were　used　in　this　paper　for　objective　evaluation　of　oil　depot　safety.　The　catastrophe　progression　theory　was　mainly　used　to　achieve　non-weight　objective　evaluation.　Because　the　catastrophe　progression　method　has　requirements　on　numbers　of　evaluation　indexes,　the　rough　set　theory　was　used　to　reduce　indexes　for　index　layer　with　excess　numbers　of　indexes.　The　following　methods　were　used　to　perform　the　evaluation　during　the　expert　marking,　the　score　interval,　the　score　distribution,　and　exact　scoring,　then　Monte-Carlo　simulation　was　utilized　to　get　the　random　score　for　the　given　interval　or　distribution,　to　achieve　the　objectivity　of　index　scores.　Finally,　multiple　evaluation　results　of　catastrophe　progression　where　the　Monte-Carlo　method　was　used　were　gathered　and　then　analyzed　to　get　the　evaluation　grade.　The　method　is　feasible　and　proved　to　be　useful　by　practical　examples.　©　2015,　Editorial　Department　of　Transaction　of　Beijing　Institute　of　Technology.　All　right　reserved.