Abstract: The calculation of earth pressure is the premise of reasonable design for excavation engineering. The earth pressure acting on the excavation support structure is not a constant value. It is related to the height, stiffness, displacement of the retaining structure. The existing earth pressure calculation method considering displacement is used to analyze the relationship between displacement of retaining wall and active earth pressure on the bracing system. The results are compared with those calculated by the China's code and the measured data. The variation of the earth pressure on the retaining wall is analyzed. The necessity of the earth pressure calculation considering displacement in the excavation engineering design is explained.