The triode, an electronic device that facilitates signal amplification or switching, has significantly contributed to signal amplification, advanced electronic technology research, practical problem-solving, and overall scientific and technological progress. This work develops a novel triode, namely a fluorescent triode, featuring a sandwich-like electrode/insulator/quantum dots/electrode architecture. It is demonstrated that compared to traditional DC voltage-based fluorescence modulation methods, using AC voltage with controlled amplitude and frequency enables more precise and efficient regulation of fluorescence output intensity. The output characteristics and transfer characteristics of this triode are similar to those of conventional field-effect transistors. Interestingly, using only a single fluorescent triode allows for the realization of AND, OR, NOT, and XOR logic gates. Furthermore, the carrier dynamics under optoelectronic effects demonstrate that the fluorescent triode achieves neuromorphic functions, including excitatory postsynaptic intensity, spike number/intensity-dependent plasticity, paired pulse facilitation, and short-term plasticity. This research extends the device architecture and function of triodes, offering considerable potential for applications in optical integrated circuits and optical computing.