Abstract: ZnO nanopowder doped with Fe, Mg and Cu were synthesized. The TEM photographs show that the shapes, diameters and diameter distributions of the doped ZnO nanopowders vary little with the metal ions, and the diameters of the particles with doping or without doping are all 30 - 80 nm, with the same statistic average diameter of 50 nm. By comparing and analyzing the UV-Vis absorption spectra of nanosized ZnO doped with different metal ions, it is found that the doping changes the absorption wavelength and transmission of ZnO nanopowder and causes obvious blue immigration or red immigration. Fe doping has the greatest influence on the blue immigration, the absorption wavelength of the nanosized ZnO doped with Fe changes from 400 nm to 315nm and the transmission at 315 -700nm increases from 0.256% to 4. 872% . ZnO doped with Mg shows a red immigration and its absorption wavelength changes from 400nm to 500nm, while the transmission at 500 -700nm increases from 0.221% to 3.816%. ZnO doped with Cu shows a blue immigration of only 20nm, and the transmission at 380 - 700 nm increases from 0.080% to 1. 471 %.