Abstract: Adopted radio frequency plasma enhanced chemical vapor deposition system（RF-PECVD）,and high pure SiH₄ as air-source separately,so that deposited polycrystalline silicon thin films on P-type ＜100＞ single silicon,when temperature of underlay is at 600℃ and electrical power of emitting-frequency 13.56MHz is 50W,adopted high temperature and vacuum-annealing to fabricate amorphous silicon thin films of nanometer crystalline grains.Took advanced of X-ray Diffraction Apparatus（XRD）、Raman Spectrum 、and AFM to measure and analyze thin-film micro-structure and surface appearance.The result of the experiment shows that the polycrystalline silicon thin films crystallized,when the annealing temperature was at 800℃,and then formed ＜111＞polycrystalline silicon thin films of selective better direction;with increasing temperature,intensity of Raman Spectrum TO and TA films weakens gradually;AFM gives that thin-film crystalline grains become significantly slender after 800℃ annealing,and formed polycrystalline films of grain sizes from 20 to 40nm,ups and downs degree of thin-film crystalline grains weakened significantly.