There are a lot of superlarge crosssection loess tunnels on BaojiLanzhou passengerdedicated railway. In this article, thestateoftheart of studies on the design of the primary support of loess tunnels on passengerdedicated railways is presented, the equivalent elastic modulus of the primary support of the tunnels is calculated by means of conversion method and simulation method, comparison and contrast is made between the calculation results obtained by these two calculation methods, the value of the elastic modulus of the primary support and the pressure of the primary support are analyzed on basis of the monitoring data of the rock mass pressure. The study results show that the equivalent elastic modulus of the primary support calculated by simulation method is more accurate. The paper can provide reference for the design and construction of similar projects in the future.