The acoustic emission signal of the mechanical seal is easily disturbed by the environmental noise,and the signaltonoise ratio is relatively low.A new denoising method based on complete ensemble empirical mode decomposition (CEEMD) and particle filter (PF),the CEEPF method was proposed.Firstly,the collected acoustic emission signals was decomposed by the CEEMD,the highfrequency IMF component was identified by using the principle of correlation coefficient,and then it was reconstructed.Then the ARIMA model was built on the reconstructed signals,which is used as the state equation.Then the measurement noise was extracted using the wavelet decomposition and reconstruction idea,and the measurement equation was established.Finally,particle filtering was performed on the reconstructed signal,and the filtered result was reconstructed with each lowfrequency IMF component to obtain a noisereduced acoustic emission signal.The results show that the denoising method based on CEEMD and PF can effectively filter out background noise of mechanical seal acoustic emission signals and preserve the effective information to the greatest extent.The simulation signal and the test signal were denoised by CEEMD wavelet threshold,standard particle filter,and CEEPF noise reduction,respectively.It is found that the CEEPF method is obviously superior to other two methods in noise reduction effect.