By calculating the seepage field around the cement-soil retaining wall, the variation law of water pressure on the wall side was studied. The results show that the water pressure coefficient is not constant along the elevation, and is seriously affected by the distribution of soil layer on the wall side and its relative permeability, the permeability of the wall foundation soil and the buried depth of the impervious layer lying down. In general, the side pressure behind the wall when considering seepage is always less than the corresponding value when seepage is not considered, and when the passive earth pressure coefficient in front of the wall is small, the side pressure on this side when considering seepage is greater than the corresponding value when seepage is not considered, so this situation is conducive to the stability of the retaining wall.