Over the last twenty-five years,tremendous progress has been made in the understanding and application of high-order harmonic generation(HHG)[1].High-order harmonic(HOH)not only offers the potential for creating new table-top coherent light sources from the extreme ultra-violet(XUV)to the X-ray region,but also provide a way to obtain the atomic and molecular structure and dynamic information by measuring the high-order harmonic spectrum itself,which is termed as high-order harmonic spectroscopy(HHS)[2].The HHG has been understood qualitatively in the terms of the three-step model(TSM),also called the recollision or rescattering model [3].