The 3 super-harmonic response of pile foundation under earthquake action was investigated. Based on Hamilton Variational Principle, the nonlinear equations of motion on pile under earthquake action were established. Then the Galerkin method was used to discrete the governing equation. The 3 super-harmonic response of pile was studied by using the multi-scale method. The effects of the soil thickness, the shear wave velocity and the frequency ratio on the seismic force were studied, and the effects of the seismic force, elasticity coefficient and inelasticity coefficient on the frequency-response curves were studied. The results are as follows: the 3 superharmonic resonance may be excited when the earthquake frequency and the pile frequency are in an almost 1:3 ratio, the 3 super-harmonic responses of pile increase with the increase of seismic force and nonelastic coefficient, but decrease with the increase of elastic coefficient.