Abstract: Disclosed by the present disclosure are Group II-III-V-VI quantum dot, preparation method therefor and quantum dot optoelectronic device. The method for preparing Group II-III-V-VI quantum dots includes the following steps: S1, providing a first solution containing a Group III-V quantum dot cores, or providing a second solution containing a Group II-III-V quantum dot cores; S2, adding a second supplementary liquid to the first solution, or adding a first supplementary liquid to the second solution, and reacting to obtain a Group II-III-V-VI quantum dot cores; wherein, reacting a first mixture at a temperature of 40˜100° C., and then adding a precursor of a first Group VI element and reacting to obtain the first supplementary liquid; or reacting a second mixture at a temperature of 40˜100° C., and then adding a precursor of a first Group VI element and reacting to obtain the second supplementary liquid.