Abstract: The non-linear relationship between displacement and soil reaction caused by pile-soil interaction directly results in the complexity of mechanical analysis of bracing pile. Through replacing the soil reaction of fourth-order differential equation of single pile displacement with the earth pressure obtained from the earth pressure theory considering displacement given by MEI, a variable-coefficient, non-homogeneous and non-linear fourth-order differential equation can be obtained. Based on different mechanical characteristics of bracing pile located at upside and downside of excavation surface respectively and initial condition of pile peak, the explicit solution of displacement for random part of bracing pile is presented with the method of Taylor series. Accordingly, the displacement of soil around the pile also can be obtained by the method of geometry. Thus, the force acting on bracing pile at any depth and any point can be calculated directly. Therefore, the solution in the paper is more simple and convenient. A numerical example is presented to verify above solution.