When tunnels cross underneath buildings, the safety of the buildings should be guaranteed. The site monitoring is carried out for parallel shield tunnels of Heping Road StationJinwan Square Station on Tianjin Metro Line No. 3 crossing underneath 3 masonry buildings; and the settlement and inclination of the buildings are analyzed when adopting 2 crossing modes, i.e. former tunnel underneath crossing + latter tunnel laterally crossing and former tunnel laterally crossing + latter tunnel underneath crossing, by fluidsolid coupling simulation method. The research results shows that: (1) When adopting the crossing mode of former tunnel underneath crossing + latter tunnel laterally crossing, the settlement and inclination of the buildings would be increased, the settlement curve of the building wall shows approximately as a oblique line, and the inclination of the building wall is two times that when adopting the crossing mode of former tunnel laterally crossing + latter tunnel underneath crossing. (2) The tunnels with the 2 crossing modes mentioned above affect the settlement and inclination of the building with large oblique crossing angle little.