A novel method to solve the inaccuracy of the measured temperature using the distributed temperature sensor system is presented.The method to eliminate Rayleigh noise i s revealed theoretically with a loop configuration and a section of the reference sensing f iber in the front section. Due to the differences between the Stokes channel and anti-Stokes channel of th e wavelength division multiplexing (WDM) and the avalanche photodiode (APD), the Rayleigh noises in Stokes light and anti-Stokes light are not th e same.By changing the temperature of the reference sensing fiber,the Rayleigh noises in Stokes light and anti-Stokes light are calculated.The demodulation temperatures of the distributed temperature sensor b efore and after the Rayleigh noise calibration are compared.The experimental results indicate that t he accuracy of the measured temperature has a great improvement after the Rayleigh noise calibratio n.The temperature errors caused by Rayleigh noise are decreased from 8.5℃ to 0.8℃ for 5times of measurement in a row,when the temperature of the sensing fiber increases from 35.0℃ to 85.0℃. With the proposed method,the impacts of the temperature inaccuracy caused by different wavelengths ,local external perturbations and the Rayleigh noises are cancelled out,and the accuracy of the measured temperature of the distributed temperature sensor system is improved si gnificantly.