Embodiments of this application disclose a light-emitting diode chip and a preparation method therefor. The chip includes: an N-type GaN doping layer; three sub-pixel structures respectively formed in three sub-pixel regions at a first surface of the N-type GaN doping layer, where each of the three sub-pixel structures includes a blue-light quantum well structure, an interface barrier layer, a green-light quantum well structure, a charge barrier layer, and a P-type GaN doping layer that grow in sequence; three P-type contact electrodes respectively formed on the three sub-pixel structures, and an N-type contact electrode formed in a remaining region other than the three sub-pixel regions at the first surface of the N-type GaN doping layer; and a red-light colloidal quantum dot structure formed in a region that corresponds to a first sub-pixel region in the three sub-pixel regions and that is at a second surface of the N-type GaN doping layer.