Soil arching effect is a key factor for the load transfer in a piled embankment. Based on the previous model test, a DEM model of a piled embankment is conducted by the PFC2D. The development of soil arching with the pile-subsoil relative displacement is analyzed based on the deflection of principal stress direction. Then, a soil arching model with a reasonable arch axis is proposed to depict the soil arching in a piled embankment. Meanwhile, a load-transfer coefficient α is introduced for the quantitative analysis of load transfer between the soil arching and the embankment fill below the arching. Numerical results indicate that the pile-subsoil relative displacement will induce the deflection of principal stress direction, which forms the soil arching in embankment. The features and heights of soil arching are related to the pile-subsoil relative displacement, and the maximum soil arching height is about 0.8 times of clear pile spacing. The decrease in α with the increase of soil arching height is found to follow a logarithmic relation.