A LED dimming method includes obtaining an illumination set according to a preset dimming curve and an initial dimming grayscale set; obtaining an excitation signal set comprising a voltage signal set or a current signal set according to the illumination set; obtaining a measured illumination curve according to the excitation signal set and the initial dimming grayscale set; collecting a subdivision dimming grayscale set according to the measured illumination curve and the preset dimming curve, so that a dimming curve corresponding to the subdivided dimming grayscale set and the illumination set coincides with the preset dimming curve; and adjusting the excitation signal set according to the subdivision dimming grayscale set. The method can achieve an ideal and undistorted optical curve effect to meet the demands of the user, and therefore achieving an efficient and accurate dimming.