A method on fusion of dual color mid-wave infrared (MWIR) images with weak signal is presented based on suprathreshold stochastic resonance (SSR). The weak signals of two images are enhanced by SSR respectively, and the noise of images is reduced with median filter. Then images denoised are fused by support value transform (SVT), and fusion image with more information and clear details is obtained. The experimental results show that local standard deviation, local entropy and peak signal to noise ratios of images obtained by the method proposed increase 247.7% , 45.52% , 6.71% and 6.65%, respectively. The validity of the method proposed is proved.