For the calculation of active earth pressure on the front wall of flexible sheet pile wharf,Coulomb earth pressure theory is adopted.Assuming that the active earth pressure on the front wall is generated by the sliding body of the soil behind the wall in the ultimate equilibrium state,a force balance differential equation is established for the horizontal differential elements taken by sliding soil along the wall height direction.Then the lateral earth pressure coefficient is solved by integrating the stress state of the micro soil elements on the deflection arch trace of the minor principal stress generated by the sliding trend of the sliding soil,and the theoretical formula for the distribution of earth pressure strength along the wall height of the flexible front wall is obtained by substituting the equilibrium differential equation.On this basis, the non-limit state soil mechanics parameters caused by the deflection of flexible wall of the sheet pile wharf are introduced to solve the earth pressure strength under non-limit state.The method proposed is basically consistent with the experimental results of mathematical models,and has certain reference significance.