Abstract: The distribution of laggings' earth pressure between supporting piles is one of the key problems should be considered during design. Based on the loads transfer relationship in the pile and lagging system, this paper presents a compound retaining structure between two adjacent supporting piles which contains a flexible load reduction cushion between soil and laggings. A finite-difference model of the compound retaining structure is established by FLAC3D, by which both the load reduction effects and the influential factors of the flexible cushion were analyzed. The results show that the flexible cushion can effectively reduce the earth pressure acting on the laggings. The load reduction effect is more significant when the elastic modulus of the flexible cushion is smaller or the thickness of the flexible cushion is larger.