In the processing of the data sampled by the distributed polarization coupling analyzer(DPCA)wavelet-transform was applied to reduce the noise.Experimental results indicate that the signal-to-noise ratio (SNR) after denoising and recovering of the signal can meet the measurement requirements through five-stage denoising using Daubechies Wavelet.The SNR is improved from 65 dB to more than 80 dB,and the gain fof SNR is more than 15 dB.As a result,the measurment sensitivity of DPCA for parasitic polarization mode coupling in fiber gyro coil is improved.