Abstract: Infrared dual waveband radiation ratio can denote the blackbody's temperature information, and can be used for temperature measurement. When using infrared dual waveband radiation ratio to measure the temperature of point target, it is difficult to achieve high-accuracy because of various kinds of noises. The recurrence plot theory was used to analyze the non-station of infrared dual waveband radiation ratio. According to the non-station of infrared dual waveband radiation ratio, the target's response signal in IR single waveband was processed by moving average filter. The IR dual waveband radiation ratio was processed by wavelet soft-threshold filter. Experimental result indicate that, when the SNR12, 1 K temperature accuracy can be achieved with above processing method for static point target, and 2 K temperature accuracy can be achieved for slow moving point target.