Most of the existing calculation methods about the earth pressure between double-row piles are depending on classical earth pressure formula,without considering the influence of friction between pile and soil.In view of the above problems,according to the ultimate balance theory,the calculation method is presented with considering the influence of friction between the soil and the pile and the width between piles to calculate earth pressure between double-row piles,and it is expanded to make it applicable to the cohesive soil,the non cohesive soil,the incompressible foundation and the compressible foundation.With the increase of width between piles,the earth pressure calculated by this method presents a curve distribution,the asymptote is close to the vertical line,and the value of earth pressure is close to the Rankine formula.Compared with the results of the finite element software Plaxis,the calculated results of the earth pressure have the same tendency,and the calculated values of the earth pressure are basically the same,which proves that the calculation method is basically reasonable and reliable,and the results are reliable.