<p>Current analytical methods for predicting the lateral deformation of diaphragm walls require complex calculation processes, including numerous parameters with uncertain accuracy, which are difficult to use in practical engineering applications. In this study, we propose a novel analytical approach for calculating diaphragm wall deformation. First, a differential element moment balance method for calculating earth pressure is proposed using a simplified calculation. The excavation effect on the sliding wedge and multiple factors of the ground were considered. Subsequently, the work performed by the earth pressure and internal support structure was calculated. Based on plate theory, a calculation model for the diaphragm wall deformation was established, accounting for the interaction between the ground and internal support structure. Finally, the analytical model was solved using the principle of minimum potential energy and the Ritz method. The proposed method was validated by comparing field measurement data with numerical simulations. A parametric study was conducted to explore the sensitivities of the influencing factors on the lateral deformation of the diaphragm wall, from which a design scheme for the diaphragm wall was presented under the given deformation control standard.</p>