In the precast reinforced high-strength spun concrete piles, (PRC piles), a numerical model on ultimate flexural condition has not been established when PRC piles have high axial force. The numerical analysis using a multi-spring model was conducted to reproduce the experimental results of six PRC pile specimens with axial force ratio ranging 0~0.313 in compression. The backbone curves of lateral load−drift angle relations were well simulated with this numerical model until ultimate condition. Furthermore, the scale effect was also investigated to see the moment capacity and post peak behavior from parametric study.