Abstract: Diaphgram wall has the advantages of small vibration, high stiffness, good integrity and fast construction speed, so it has been widely used in excavation retaining structures of deep foundation pit. Arc diaphragm wall belongs to space frame structures. Based on the classical shell theory, the differential equation of static equilibrium is deduced, and the new method for calculating the displacement of arc diaphragm wall is proposed. For the arc diaphragm wall of deep foundation pit at the east side of Nanchang Honggu tunnel, this new method is used to calculate its lateral displacement, and it is compared with the monitoring data. The feasibility and precision of the new method are investigated. The results show that the calculated values of the arc wall by this method has the same trend as the monitoring data, and the difference is just small. The proposed method is feasible , and the calculated results of the lateral displacement at the cross position is more consistent with the measured value.