A method for manufacturing a quantum-dot element utilizes a reaction chamber for evaporating or sputtering at least one electrode layer or at least one buffer layer on a substrate. A substrate-supporting base is located inside the reaction chamber for fixing the substrate. An atomizer has a gas inlet and a sample inlet. More specifically, the gas inlet and the sample inlet feed the atomizer respectively with a gas and a precursor solution having a plurality of functionalized quantum dots, and thereby form a quantum-dot layer on the substrate. The method for manufacturing a quantum-dot element forms a quantum dot layer with uniformly distributed quantum dots and integrates the processes for forming the quantum-dot layer, the buffer layer, and the electrode layer together in the same chamber.