Based　on　the　measured　data　of　surrounding　rock　pressure　and　deformation　in　the　segment　of　Longxia　Railway　at　Xiangshan　extra-long　tunnel　that　is　buried　deeper　than　500　m　with　high　development　of　geological　structure,　studied　the　characteristics　of　surrounding　rock　pressure,　formation　mechanism　of　the　deformation　pressure,　etc.,　in　the　segment　of　the　deep　tunnel　with　high　development　of　geological　structure　are　studied.　The　research　shows　that:　in　the　deep　segment　of　tunnel,　large　deformations　happen　in　the　sections　with　lots　of　structure　planes,　folds,　reversed　faults　and　little　ground　water,　after　the　excavation,　even　though　the　surrounding　rock　strength　is　higher.　The　larger　surrounding　rock　deformation　is　contributed　by　the　opening　and　volumetric　dilatancy　of　the　structural　planes,　which　are　compacted　by　the　self-weight　stress　and　residual　tectonic　stress,　as　the　lateral　confinement　is　eliminated　after　the　excavation.　For　that,　great　deformational　pressure　from　the　surrounding　rock　may　be　exerted　to　the　primary　support.　The　surrounding　rock　pressure　in　the　above　segment　has　the　following　characteristics:　(1)　The　surrounding　rock　pressure　is　greater　in　the　sections　with　little　ground　water　than　the　sections　with　a　lot.　(2)　The　surrounding　rock　pressure　largest　on　the　arch　crown　to　the　hance　in　the　sections　with　syncline　that　developed　in　the　tunnel　longitudinal,　the　nearer　to　the　core　of　the　syncline,　the　greater　the　pressure.　(3)　In　the　sections　developed　with　folds,　the　surrounding　rock　pressure　is　larger　in　the　direction　perpendicular　to　the　fold　axis.　(4)　In　the　sections　developed　with　reversed　fault,　the　surrounding　rock　pressure　is　larger　in　the　side　that　opposite　the　fault　dip;　and　the　surrounding　rock　pressure　in　the　position　of　fault　surface　is　largest　in　this　side,　smallest　in　the　other　side.　(5)　The　surrounding　rock　pressure　on　the　lower　bench　is　smaller　than　that　on　the　upper　bench,　the　longer　the　time　between　the　excavations,　the　greater　the　difference　between　the　pressure.