The invention discloses a measuring method and device of LED absolute optical power spectrum distribution. The device comprises a pickup optical fiber head, a color filter and a driving motor thereof,a photocell, a left optical fiber and a right optical fiber, a color filter hole in a color disc and the right optical fiber are on the same optical axis, namely the left optical fiber and the rightoptical fiber are aligned, the center of the small hole of the middle color disc is arranged on a center connecting line of the optical fibers, the rotatably color disc is provided with a plurality ofsmall holes, color filters of different absorption rates are arranged in the small holes, the end of the right optical fiber is connected with the photocell, the photo cell receives light and can output electricity, and the voltage is in direct proportion to the illuminance. According to the method and device, accurate white-light LED absolute spectrum distribution is obtained by adopting measurement with less times, and compared with a spectrometer, the price of the device is greatly reduced, the method is simple, the usage is convenient, the size is small, and the device is very applicableto occasions in need of real-time detection.