Tunnel construction monitoring on sit is was carried out by means of high precision total station and reflective film, with the monitoring of Dunliang tunnel as an example. The advantages, disadvantages and applicability of the double side drift method, single side drift method and threebench excavation method for loess tunnel with large crosssection are put into comparison, on basis of monitoring data analysis. Key deformation control technologies of different construction methods are obtained. The paper can provide references for similar projects in the future.