Based　on　the　optimization　emergency　management　legal　mechanism　of　environment　emergency,　we　introduce　the　Apriori　law　to　the　emergencies　analysis,　and　use　support　degree　and　confidence　degree　to　improve　the　Apriori　law,　so　the　law　has　stronger　relevance.　We　use　the　VC　software　to　programming　mathematical　model　of　the　law,　and　use　VC　source　code　and　engineering　design　model　to　design　the　computer　optimization　system　of　environmental　emergency　management　legal　mechanism.　In　order　to　verify　the　effectiveness　and　reliability　of　the　system,　we　do　correlation　calculation　on　legal　mechanism　before　and　after　optimization,　and　obtain　the　correlation　visualization　process　curve　of　Apriori　law,　and　obtain　the　optimum　structure　of　environmental　emergencies　legal　mechanism.　It　provides　a　new　computer　method　for　studying　environmental　emergency　management.　©　(2014)　Trans　Tech　Publications,　Switzerland.