Abstract: Based on the foundation pit project of West Wenyi Road Tunnel in Hangzhou, the supporting characteristics and effects of segmental diaphragm walls in strip foundation pits are investigated by using the finite element analysis method. The results show that the horizontal deformation of the diaphragm walls in different sections exhibits a drum belly distribution law, and the maximum horizontal deformation decreases with the increase of the buried depth of the diaphragm walls. The settlement law of the surface soil near the diaphragm walls in different sections is basically the same, with a concave curve distribution. The buried depth of the diaphragm walls only affects the settlement value, but does not affect its distribution law. If the segmental diaphragm walls with different depths are set at the long side of the strip foundation pit, the surface settlement and horizontal deformation of the diaphragm walls can still meet the engineering safety requirements and have certain economic benefits.