MIB　is　the　main　operating　target　of　extension　agent.　MIB　management　performance　directly　determines　the　overall　performance　of　the　agent.　By　analyzing　the　characteristics　of　extension　agent＇s　MIB,　this　paper　proposes　a　multi-domain　binary　sort　tree　storage　strategy　and　studies　the　search　and　traversal　algorithm　of　MIB　node　under　the　storage　strategy.　Analysis　shows　that　the　strategy　can　effectively　improves　search　and　traversal　efficiency　of　MIB　node.　For　solving　the　issue　of　MIB　region　registered　conflict,　this　paper　proposes　region　decomposition　strategy　and　ensures　the　flexibility　and　reliability　of　the　agent.