Deep　excavation　engineering　is　a　dynamic　and　complex　system　where　the　soil　and　the　support　structure　interact.　By　analysis　of　information　of　monitoring　and　surveying,　the　distortion　of　the　earth　can　be　learned　and　the　change　direction　can　be　forecasted.　Deep　excavation　of　East　Diaoyutai　Station　on　the　9　th　line　of　Beijing　subway　is　taken　as　an　example,　workers　inspected　earth　surface　displacement　around　deep　excavation,　horizontal　displacement　of　stake　body,　horizontal　displacement　of　stake　peak,　and　steel　brace　axis　stress　on　the　scene,　and　then　analyzed　the　data.　And　then　work　state　of　support　structure　can　be　mastered　at　any　moment,　which　can　guide　the　excavation　and　construction.　©　2011　IEEE.