The　successful　completion　of　the　Zhengzhou-Xi＇an　high-speed　railway　project　has　greatly　improved　the　construction　level　of　China＇s　large-section　loess　tunnels,　and　has　resulted　in　significant　progress　being　made　in　both　design　theory　and　construction　technology.　This　paper　systematically　summarizes　the　technical　characteristics　and　main　problems　of　the　large-section　loess　tunnels　on　China＇s　high-speed　railway,　including　classification　of　the　surrounding　rock,　design　of　the　supporting　structure,　surface　settlement　and　cracking　control,　and　safe　and　rapid　construction　methods.　On　this　basis,　the　key　construction　techniques　of　loess　tunnels　with　large　sections　for　high-speed　railway　are　expounded　from　the　aspects　of　design　and　construction.　The　research　results　show　that　the　classification　of　loess　strata　surrounding　large　tunnels　should　be　based　on　the　geological　age　of　the　loess,　and　be　determined　by　combining　the　plastic　index　and　the　water　content.　In　addition,　the　influence　of　the　buried　depth　should　be　considered.　During　tunnel　excavation　disturbance,　if　the　tensile　stress　exceeds　the　soil　tensile　or　shear　strength,　the　surface　part　of　the　sliding　trend　plane　can　be　damaged,　and　visible　cracks　can　form.　The　pressure　of　the　surrounding　rock　of　a　large-section　loess　tunnel　should　be　calculated　according　to　the　buried　depth,　using　the　corresponding　formula.　A　three-bench　seven-step　excavation　method　of　construction　was　used　as　the　core　technology　system　to　ensure　the　safe　and　rapid　construction　of　a　large-section　loess　tunnel,　following　a　field　test　to　optimize　the　construction　parameters　and　determine　the　engineering　measures　to　stabilize　the　tunnel　face.　The　conclusions　and　methods　presented　here　are　of　great　significance　in　revealing　the　strata　and　supporting　mechanics　of　large-section　loess　tunnels,　and　in　optimizing　the　supporting　structure　design　and　the　technical　parameters　for　construction.　(C)　2018　THE　AUTHORS.　Published　by　Elsevier　LTD　on　behalf　of　Chinese　Academy　of　Engineering　and　Higher　Education　Press　Limited　Company.