The outside noise of certain scrap handler is bigger, the noise source must be determined to reduce the noise. Noise pressure signals in the front, back, right, and left of the scrap handler are measured and the frequency analysis is completed. Using the combining method for multi-directional noise signal analysis, the machine running characteristics and the layout of machine structures, the noise source can be determined. Results indicate that the outside noise of the scrap handler is composed by the noise spreading both from muffler of engine and fan system. Based on the frequency characteristics of the two noise sources, the tiny perforation resonance structure is chosen to reduce the outside noise, and the muffler and noise insulator are designed and installed. The noise of the scrap handler reduces by 5.8 dB, thus it achieve the newest noise standard in Europe.