Research conclusions: The introduction of the concept of " Loose Soft Soil" in the loess investigation，has made a supplement and improvement for“Code for Geology Investigation of Railway Engineering”． At home and abroad for the first time using the embedded consecutive pile － sheet subgrade structure，to solve the long － term creep resistance of the thick layer of clay soil under the subgrade base which would cause the settlement of subgrade． Comprehensively and systematically put forward the design principles and construction method of the large section of loess tunnel which is safely，rapid and economical． In the high － intensity earthquake zone and on the long continuous － beam bridge，the technology of four sets two － way rail expansion joint were used． In the north Weinan station，integrated design technology of pass － type station bridge and gapless turnout group was applied． These innovative technologies are the key to the technology package of civil works for high － speed railway built in collapsible loess regions．