Double-row-pile retaining structure is a space system with large lateral rigidity, which can effectively control the deformation of the foundation pit, especially in the soft soil area can better control the horizontal displacement of piles. Based on the engineering of deep foundation pit design in Haikou soft soil area, the retaining form of double-row-pile + three axis cement mixing pile + passive zone reinforcement is proposed, the design parameters are discussed, the plane rigid frame structure model is established by using the elastic foundation beam method of Wenkler assumption, and the bending moment, shear force and displacement of front & back-row-pile are calculated. Through the deep horizontal displacement monitoring, the model value and the monitoring value of the displacement are analyzed comparatively. The results show that it can effectively control the lateral deformation of the retaining structure, reduce the bending moment and shearing force of the pile body, and reduce the impact on the surrounding environment, which can be used for reference for the deep foundation pit engineering in Haikou soft soil area.