The construction technologies for the shallow largespan underwater section of Xiangjian rivercrossing tunnel at Yingpan road are studied, and the excavation of the tunnel section is simulated by means of 3D model, so as to guarantee the construction safety and to select proper construction organization and proper construction method. The analysis on the calculation and monitoring data proves that the 14step excavation method, doubleshell support technology and transitional section excavation technology adopted in the tunnel construction are rational. For the sake of the construction technologies mentioned, the safety and stability of the shallow largespan section of Xiangjiang rivercrossing tunnel are guaranteed.