Laser-ion acceleration has been the focus of inteational research[1-3] for many years.However,obtaining mono-energetic proton beams larger than 100MeV is still a challenge.Although the field strength in laser-plasma acceleration is 3-4 orders higher than that in classic accelerators,it quickly decreases to zero in 1-2 pulse durations for target normal sheath acceleration (TNSA),[2-6] which is dominated in the parameter region ao 《 σo =(n)e(l)e,where ao =eEl/mwc,El is the electric field of the laser pulse,w is the laser frequency,e is the elementary charge,m is the electron mass,c is the light velocity in vacuum,no is the initial plasma density,the normalized electron density (n)e=ne/nc,(l)e =le/λ,nc is the critical density,A is the wavelength,ne is the electron density,and le is the thickness of the electron layer.In the TNSA model the thermalized electron cloud leads to ion acceleration,and then ion energy dispersion cannot essentially be improved.Although specially designed targets are used,the relative energy can only be improved to 15％[7] or 17％.[2] As a promising method to generate relativistic mono-energetic protons,radiation pressure acceleration (RPA) has attracted more attention[3,8-15] and becomes dominant in the interaction between the ultra-intense laser pulse and thin foils if ao (=) σo.