In this paper, we study the structure distortion, including the atomic potential, energy level and wavefunotion of hydrogen atom in a strong converging laser field of linear polarization. It is shown that the modified atomic potential is equal to a potential decided by an oscillating spherical surface with maximum radius of R0∝I1/2ω-2 and nuclear charges. With such a new potential, the atomic energy levels shallow and split, the wavefunction undergoes strectching in space drastically.