A method of patterning quantum dot layer includes: forming, on a substrate, a film layer including a photosensitive material and quantum dots with ligands on surfaces of the quantum dots; irradiating a quantum dot reserved area with light of a preset wavelength; where under irradiation with light of the preset wavelength, the photosensitive material or a product of the photosensitive material after light irradiation reacts with the ligands on the surfaces of the quantum dots, to allow the ligands to fall off from the surfaces of the quantum dots, so that solubility of the quantum dots is changed to cause the quantum dots to undergo coagulation; and removing a portion of the film layer which is not irradiated by the light of the preset wavelength, to form a patterned quantum dot portion of the quantum dot layer in the quantum dot reserved area.