A multiwavelength quantum dot laser element is provided. A perpendicular stack of quantum dot active regions with different light emitting wavelengths is employed, and thickness, material composition, and quantum dot size of each of the quantum dot active regions are modulated, so as to form various laser oscillation conditions. When a current applied to the quantum dot laser element is larger than the start-oscillation current condition, lasers with different wavelengths are simultaneously obtained in each of the quantum dot active regions, thereby achieving the application of the multiwavelength quantum dot laser element.