Abstract: Empirical Modal Decomposition (EMD) method is introduced to analyze power signal, which can eliminates the white noise and harmonics in the power signal. Firstly, power signal is dealt with by using of EMD, and the white noise is filtered according to statistical characteristics of Intrinsic Modal Function (IMF) after decomposing. Then the remanent IMF can recombined, and new signal will be decomposed by empirical modal. Without the influence of the white noise, the harmonic and fundamental components of the new reset signal can be decomposed in different IMF by EMD, and the IMF of lowest frequency is the required fundamental component, then the harmonics in the power signal can be eliminated. The result of experiment verifies the validity and correctness of the proposed method.