Affected　by　the　water　content　and　saturation　degree,　the　dualistic　structure　of　loess　is　formed　naturally　around　sub-water.　Through　taking　dualistic　structure　of　collapsed　loess　in　Xi＇an　as　an　example　and　indoor　3-axis　experiments,　the　physical　and　mechanical　properties　of　dualistic　collapsed　loess　are　analyzed.　It　is　proposed　that　the　deformation　in　dualistic　loess　structure　can　be　coordinately　investigated　by　using　Bingham　body　model　and　Biot　consolidation　theory,　and　this　method　is　also　applied　in　the　analysis　of　shielding　construction　in　Xi＇an　metro.