Abstract: ZnO thin film is a new type of wide bandgap oxide semiconductors, it has excellent physical and chemical properties. It has potential applications in the low-light-level image intensifier. It was found that ZnO thin film can be used as the buffer layer to fabricate GaN UV photocathode with high performance by the investigation on the lattice parameter of ZnO material. It was indicated that ZnO thin film could be used as the negative-affinity (NEA) photocathode itself. Once the p-type ZnO obtained, it was more benefit for the formation of NEA photocathode. Furthermore, according to the Monte Carlo simulation results, it was shown that the stopping ability of ZnO thin film on positive ions was stronger than that of traditional Al2O3 ion barrier film. So ZnO thin film can substitute for Al2O3 thin films and be used as the ion barrier film in the third generation low-light-level image intensifier. It is also found that ZnO can be used as the dynode due to its high secondary electron emission and suitable resistivity.