The multifractal approach was used to describe the failure process of organic thin film electrolu-minescence observed with fluomicroscope dynamically.It was found that the failure of the electrolu-minescence resulted from the bubbles generated at the interface between the organic layper and the metal electrode.The bubbles became more and more numerous during the device working.Multifrac-tal spectra showed that the longer the working time or the higher the loaded voltage of the device,the narrower the spectrum.This result was in good agreement with the experimental observation.