Combined　with　the　monitoring　example　of　a　deep　excavation　in　Beijing,　the　design　and　the　instrument　layout　were　introduced.　The　working　content　of　the　monitoring　frequency,　the　values　of　alertness　and　the　displacement　prediction　were　presented.　During　deep　excavation,　the　frequency　and　time　were　added　when　the　demands　were　needed.　The　unusual　data　were　analyzed.　The　dangerous　forecast　would　be　made　if　the　data　were　close　to　the　values　of　the　alertness.　To　ensure　the　effective　excavation　the　pit　and　the　environmental　safety,　active　debates　were　carried　out　and　suggestions　were　suggested.