Despite major progress in optical encryption using light-emitting materials, rewritable displays with mode-selective emissions remain rare. We present a rewritable triple-mode light-emitting encryption display utilizing stimuli-responsive fluorescence (FL), room-temperature phosphorescence (RTP), and electroluminescence (EL). The display includes coplanar electrodes with a gap, an FL phosphor-polymer composite (EL/FL layer), and a solvent-responsive RTP additive-polymer composite (RTP layer). Upon 254 nm UV exposure, dual FL and RTP emissions are triggered. Applying a polar solvent (excluding water) and an AC field activates EL, enabling triple-mode emission. Water deactivates RTP, switching the display to dual-mode (FL and EL). Emission modes are rewritable by solvent evaporation. The display enables secure full-color encryption, with information revealed only when the emission modes are correctly aligned, meeting the need for multi-mode light-emitting security displays.