In order to restrain the temperature excursion accumlation and Anti-Stokes back scattering intermingled with Rayleigh back scattering,a new type of demodulation method for distributed fiber Raman temperature sensor is proposed.By this method,which is named as circulated demodulated method(CDM),the Anti-Stokes optical time domain reflectance (OTDR) curves is demodulated by Rayleigh OTDR curves.The remedy increases the temperature precision,stability and sensitivity of system,reduces the cost of the system.The experiment results agree with the theory and the precision reaches at ±0.05℃.