This paper pointed out and verified the limitations of the spectrum auto-correlation (SAC) method based on the analysis process of empirical mode decomposition (EMD) and mechanism of bearing fault. Then, a feature extracting method of bearing fault diagnosis combined with EMD and SAC (EMD-SAC) was proposed, which analyzed the intrinsic mode function (IMF) based on EMD and chose the appropriate component to analyze using SAC. With this method, the bearing failure frequency could be separated from the complex signal. Finally, the inner and outer ring fault of deep groove ball bearings and cylindrical roller bearings respectively were tested in laboratory. The fault vibration data was measured and analyzed to verify the theoretical analysis presented above.