Abstract: On the basis of the assumptions of Rankine's earth pressure theory and the Limit Equilibrium theory, the limited width soil is translated into the semi-space soil, so that their horizontal earth pressures are fitted to each other. Then, as an example, a deep foundation pit to protect the limited width soil is designed and constructed according to the software of pit-retaining. In addition, large-angle anchors and double-row piles at certain place are applied in this design. As a result, the monitored horizontal displacements are all within the standard limit of design, therefore it can be a reference for similar projects.