Abstract: The action point of the Coulomb active earth pressure used to be determined at the one-third place of the wall height, and the analysis in this paper shows that this practice is not reasonable. In order to solve this problem, considering the forces on the sliding soil wedge behind the wall, based on the balance of three converging forces, the relations between the earth pressure distribution of the wall back and the distribution of the soil wedge pressure on a stable soil behind, and the geometric relationship, the expression of the position of the action point of the active earth pressure is obtained; the sensitivity of the height of the action point to the impact factors is analyzed, which shows that the sensitivity sequence from big to small is the inclination of the wall back, the angle of the internal friction, the angle of the external friction, and the angle of the fill slope.