Disclosed is a method for producing a high-luminance monochromatic light based on optical wavelength conversion, which is used in a light source comprising an excitation light source, and comprises the steps of: setting a first wavelength conversion material and a second wavelength conversion material; using an excitation beam to excite the first wavelength conversion material and the second wavelength conversion material, wherein the first wavelength conversion material absorbs the excitation light to produce a first excited light; the second wavelength conversion material absorbs a first waveband portion of the first excited light to produce a second excited light, where the energy of the absorbed first waveband portion is more than 50% of the total energy of the first excited light; mixing the second excited light and the unabsorbed portion of the first excited light together to form the high-luminance monochromatic light.