ZnO and Fe-doped ZnO thin films are prepared on glass substrate by sol-gel method, and the surface morphology, structure and optical property are analyzed by scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and UV-Vis-NIR spectrophotometer. The results show that both films have a smooth surface and a hexagonal wurtzite structure with orienting along the (101) plane. Compared with the ZnO film, the surface of Fe-doped ZnO film becomes smoother, and its grain size decreases from 58.512 nm of the ZnO film to 36.460 nm. Moreover, after Fe doping, the orientation degree of (101) plane is weakened, and the optical band gap energy increases from 3.1 eV of the ZnO film to 3.4 eV.