Abstract: In order to study the influence of vehicle dynamic load on the deformation behavior of large-diameter shield tunnel in soft soil layer, this paper takes a tunnel project in Zhongshan section of Pearl River Delta as the background, establishes a three-dimensional finite element model based on actual geological conditions, and studies the deformation response of tunnel under vehicle dynamic load. By simulating the tunnel deformation under different driving paths (across the tunnel, parallel tunnel) and different load levels (standard load and overload 5%~30%), the influence of vehicle position and load size on tunnel structure is analyzed. The results show that the vertical displacement and ovality of the tunnel increase linearly with the increase of vehicle load, and the deformation of the tunnel across the tunnel is larger than that of the parallel tunnel. The closer the vehicle is to the center line of the tunnel, the greater the settlement of the tunnel; when crossing the tunnel, when the overload is less than 15%, the vertical displacement of the tunnel caused by vehicle load is less than 15 mm; when the parallel tunnel is running, the vertical displacement of the tunnel caused by the load is less than 15 mm under the condition that the overload is less than 25%, which meets the requirements of the specification. This study can provide theoretical basis and data support for vehicle dynamic load control and safety assessment during shield tunnel construction in soft soil area.