In order to improve the mechanization degree of underground tunnel construction with shallowcover mining method, the equipment composition and construction process of the underground excavation trolley which is firstly applied to tunnel of No. 15 Bid Section of Xi′an Metro Line No. 5 are introduced. Comparative analysis is made on the construction efficiency, safety, energy consumption, deformation control of surrounding rock and the improvement of operating environment for traditional manual excavation and underground excavation trolley. The applicability of the underground excavation trolley to hydrogeology, construction crosssection, construction method, loweringdown and right angle turning in the tunnel are analyzed. Meanwhile, the improvement suggestions are put forward for the underground excavation trolley in terms of mucking system, digging bucket, milling head, remote controller, automatic shrinkable wire coil, underground excavation flexibility, etc.