Abstract: A calculation method taking laterally loaded piles as beams on elastic foundation was established, which could consider degradation of bending stiffness of piles after flexural cracking and the non-linear relation between soil resistance and displacement simultaneously. Then, the solution was achieved by the finite difference method. Regardless of the impact of soil, a bending test of a PHC pile as a simple supported beam was simulated. The results indicated that it was reasonable and feasible to simulate nonlinear characteristics of concrete beams on elastic foundation adopting the stiffness degradation model suggested by GB 50010-2010 Code for Design of Concrete Structures (revised in 2015). Further,a laterally loading test of a PHC pile in soft clayey soil was analyzed. It is shown that the curve between horizontal loads at pile heads and displacements considering stiffness degradation of piles was closer to the test results compared with that one only considering the non-linear relation between soil resistance and displacement. The impact of stiffness degradation on laterally loaded reinforced concrete piles was more significant. Therefore, the analysis method was valuable for analyzing laterally loaded test of piles and designing deflection-controlled reinforced concrete piles.