In this paper, a modified method of analyzing vertical beam on elastic foundation for the calculation of the quay wall of sheet pile is presented.In the method, the calculation of the soil pressure in front of the wall is based on the method of m, and the pressure is limited not to exceed the value of passive earth pressure. The detailed calculation procedures are introduced The calculations and analysis of engineering structures show that the difference of the results by the modified method and the original method is noticeable when the surface soil in front of the wall is hard (the value of soil's m is higher)