This　article　adopts　the　method　of　＇Local-Global　optimization＇　to　analyze　the　energy　system　of　ice　storage　air　conditioning　of　China　World　Trade　Center　Phase　3　by　the　tool　of　eQuest　energy　consumption　simulation　software.　We　found　the　influential　factors　of　the　air　conditioning　system　through　the　actual　measurement　and　simulation　analysis　results　of　energy　consumption　of　air　conditioning　system.　Then　we　adopt　the　method　of　＇Local-Global　optimization＇　from　the　Angle　of　energy　system　and　combine　with　the　actual　condition　of　the　ice　storage　air　conditioning,　we　make　three　optimization　scheme,　which　are　reducing　cooling　water　temperature　difference,　adopting　variable　flow　rate　chilled　water　pumps,　and　improving　the　fan　delivery　ratio.　And　then　we　analyze　energy　consumption　change　of　three　schemes　and　find　out　the　interactive　effect　of　the　local　system.　Finally,　we　sort　the　energy　saving　effect　and　find　out　the　optimal　overall　optimization　scheme.