Static and dynamic FEM analysis is made on the rock base and concrete lining of a waterconveyance tunnel in order to evaluate the feasibility to build a railway crossing above the waterconveyance tunnel and to evaluate the effect of the moving train on the safety of the reinforced concrete structure of the underlying water conveyance tunnel. The variation rules of the maximum displacement, the maximum principal stress, the vibrating displacement and the vibrating velocity of the particles of the rock base and concrete lining under the load of the moving train are analyzed in detail. Conclusions drawn are as follows: The maximum stresses on the rock base and concrete lining induced by the moving load of the train is less than the allowable stress of the materials; The curve of vibration displacement VS vibration velocity has an obvious threestage feature, and the characteristic point of the vibration curves basically matches with the corresponding time under the same train speed; The influence depth of the vibration displacement increases as the train speed increases, while the decay time reduces as the train speed increases; The construction of the railway above the waterconveyance tunnel has little effect on the safety of the reinforced concrete lining structure of the waterconveyance tunnel and therefore no further consolidation is needed.