Silver (Ag)-nanopracticles (NPs) are adsorbed on the exterior of ZnO nanorods (NRs) grown on glass substrates and the field electron emission (FEE) properties of the silver-NPs adsorbed ZnO NRs were investigated. The Ag-NPs adsorbed ZnO NRs were composed on glass substrate by simple photochemical method. The FEE research reveal the turn-on electric fields of ZnO NRs without and with Ag-NPs adsorption were decreased from 3.2 to 2.5 V/μm in the darkness. When exposing UV light, the turn-on electric field is decreased from 3 to 1.7 V/μm. This could be due to the improved FEE properties of Ag-decorated ZnO NRs were chiefly caused by lower effective work function, formation of quantum well and increased emitter points by attachment of Ag nanoparticles protrusion. The developed device in this study has the potential for internet of things (IOT) application.