The work aims to develop an anti-interference technology for surface acoustic wave (SAW) temperature sensor so as to improve the stability of temperature measurement. The characteristics of surface acoustic wave resonator (SAWR) response were analyzed, and the entropy energy model of SAWR response was established. The attenuation process of SAWR response corresponded to the rising process of entropy energy. The monotonous rising process of entropy energy disappeared when the response signal reached the noise level. An improved auto-correlation algorithm was designed to reduce the influence of the sinusoidal interference. The designed algorithm can remove the noise when maintaining the decay characteristics of the resonator response and the equal-amplitude characteristics of the interference signal. The detection threshold (Vthre=1) of the SAWR response signal was set up based on the simulation results and the Monte Carlo simulation experiments were performed on the threshold value. Simulation results showed that when the signal to noise ratio (SNR) was greater than 4dB, the SAWR response detection rate reached 86%, and false detection rate of the sinusoidal interference was less than 0.5%. Finally, the proposed algorithm was used to detect the actual sinusoidal signal and SAWR response. The false detection rate was close to 0. The experimental results show that the designed algorithm can be used as the anti-interference technology of SAW temperature sensor.