A thresholding method for infrared target image is proposed,which is based on the within-class absolute difference,the area difference between background and target,and Niche chaotic mutation particle swarm optimization (NCPSO).The less within-class absolute difference can make the cohesion performance better,and the area difference between background and target is used to inhibit the tendency of an equal division. Therefore,a more reasonable threshold selection rule is formed comprehensively. First,one-dimensional threshold selection method is proposed. The anti-noise performance is improved obviously by extending to the two-dimensional histogram from one-dimensional method. Then the computational burden of finding optimal threshold vector is large for the two-dimensional thresholding,thus NCPSO is used to find the optimal threshold vector. Finally,the proposed method is compared with Fisher method,the Otsu method and the maximum entropy method. The experimental results show that the proposed method is effective for less target infrared image thresholding and the running time is significantly reduced.