The effect of 248 nm excimer laser irradiation on the photoluminescence and electrical properties of ZnO thin films under different atmospheres (air, oxygen and nitrogen) is investigated. Based on Gaussian curve, the photoluminescence spectra of ZnO thin films irradiated by laser under different atmospheres are fitted, and the photoluminescence peaks around 3.31, 3.28, 3.247, 3.1 eV are assigned and analyzed in mechanism. After laser irradiation, ultraviolet (UV) emission is obviously lower and shows a little red-shift, while D0X-1LO and D0X-2LO transitions merges into one peak. After laser irradiation under oxygen rich atmosphere, the acceptor density of ZnO thin films increases, and the donor density decreases. After laser irradiation under oxygen deficiency atmosphere, the acceptor density of ZnO thin films decreases, and the donor density increases. After laser irradiation, the resistivity of ZnO thin films is decreased by three orders of magnitude, carrier concentration is increased by two orders of magnitude, and carrier mobility is increased by one orders of magnitude.