The invention provides an apparatus and method for measuring the repolarization rate of a one-dimensional material. According to the method, the interference of left-(right-)rotated elliptically polarized light and scattered light of the one-dimensional material is used, and the contributions of the real parts (imaginary parts) of the repolarization rates in two groups of results are opposite (same), thereby quantitatively measuring the repolarization rate of the one-dimensional material. The device comprises a light source, a first polarizing film, a quarter wave plate, a first polarization maintaining lens, a sample of the one-dimensional material to be measured, a second polarization maintaining lens, a second polarizing film and a spectrometer. Alternatively, the apparatus includes a light source, a first polarizer, a quarter wave plate, a beam splitter, a polarization maintaining lens, a sample of the one-dimensional material to be tested, a second polarizing plate, a mirror, anda spectrometer. According to the invention, the measurement of the repolarization rate of the one-dimensional material is realized for the first time, and the device has the characteristics of high measurement speed, wide measurement frequency band (1.6 eV-2.7 eV), no damage to the sample to be measured, simple operation and easily available equipment.