In the fiber Raman distributed temperature sensor system,the spontane ous Raman scattering signal is weak and easily lost within the background noise.To solve this proble m,an algorithm based on independent component analysis (ICA) is presented.First,add a sine signal in f ront of the spontaneous Raman scattering signal.Then the changes of the prefix sine signal′s amplitude and phase after fast ICA are used to correct the spontaneous Raman scattering signal′s amplitude and phase.Thus the Raman scattering signal is fully recovered from the background noise.In the sim ulation system of a 20－km－long fiber Raman distributed temperature sensor sys tem,the signal-to-noise ratio (SNR) of the Raman scatt ering signal can be increased by 6.09dB from 14.90dB to 20.99dB.The results s how that this method can effectively improve the SNR of Raman temperature measurement system.