The method to detect small moving targets in infrared image sequences that contain moving nuisance objects and background noises is analyzed in this paper. An infrared small target detection algorithm combined with temporal and spatial domains is put forward. On the basis of the background change slowly, the algorithm firstly confirms the object region based on the third central moments of frame difference, and decomposes the frame difference image by nonsubsampled Contourlet transform to define the energy coefficients of the sub-band images. Then the image based on the energy value of each pixel is obtained. Finally, the final detecting of the target is realised according to the different features of small targets, backgrounds and noises. The results indicate that the small infrared target detection based on nonsubsampled Contourlet transform can precisely detect the small infrared target and has better target detection performance. When the small targets with invariable and moving backgrounds are detected, the detection rate of the proposed algorithm can reach 98% and 97% and the mean of false alarm points is only 0.05 and 0.17, respectively.It concludes that the proposed algorithm can detect the small target when the target has fast or anomalistic movement.