Abstract: Taking the diaphragm wall construction of a station in Suzhou metro line 5 as research background, the measures of enhancing guide wall stiffness, selecting suitable machinery, dividing relatively small trench panel, trenching stagger and controlling slurry parameters were adopted. The effects of the length of trench, the friction angle of soil and the height difference of mud liquid level on the trench stability were analyzed. Onsite monitoring was used to detect the horizontal displacement of soil, surface settlement, building settlement and building tilt. The ground stability and the deformation law during the diaphragm wall construction were investigated and evaluated. The results show that the construction disturbs the ground at shallow depth pronouncedly, which causes the significant lateral ground movement with the maximum lateral ground movement at the ground surface. The deep soil is less disturbed, and the movement is decreased with the increasing of depth. The ground movement is under the controllable range due to the adopted measures.