The ZnO seed layers with different Bi3+-doping concentrations were prepared by Sol-Gel method, and wurtzite structured ZnO nanorods were synthesized by hydrothermal method. The X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and photoluminescence (PL) spectrum were used to measure and characterize the structure, morphology and optical properties of the samples. The results show that the nano ZnO films grown on the Bi-doped ZnO seed layer with different concentrations has no change in the crystal structure of ZnO, which is hexagonal wurtzite structure, and the peak intensity of (002) crystal surface is significantly higher than that of other crystal surfaces. It was found by FESEM that the hydrothermal growth of nano ZnO films on the seed layer of Bi-doped ZnO with different doping concentration is in the shape of nanorods. The PL spectrum shows that the peak values of near ultraviolet (UV) emission and lattice defect increase obviously with increase of the amount of the Bi-doping, and the red shift phenomenon occurs. The band gap width decreases with the increase of the amount of Bi-doping, which indicates that Bi3+ can effectively adjust the band gap width of ZnO.