Along with the promoting of The Belt and Road initiative, the construction of transnational transportation channel becomes one of the key links in the implementation of the initiative. However, the existing experience can not fully meet the construction requirement of transnational transportation and urban infrastructure under complex geological conditions. The necessity and benefit of ChinaNepalIndia Railway Channel passing through Nepal and linking China and India are analyzed; and then the preliminary design of the railway is completed. The construction difficulties, including large slope, complex geological structure, poor infrastructure construction condition and bad construction environment, a large number of long and deep tunnels and largespan bridges and complex environment and climate conditions, are summarized. Furthermore, the construction feasibilities of tunnels and bridges along the line are analyzed; meanwhile, some construction advices, i. e. mainly TBM method and supplemented drilling and blasting method and proper construction method selection for bridge scheme, are proposed.