The paper presents an efficient algorithm to detect small infrared target based on the principle of background prediction and image blocking according to the feature of small IR target in a complex background.Using the edge detection,maximum mean algorithm and partial similar methods,this approach can obtains a more accurate background.With the adoption of the statistical segmentation method,the proposed method can obtain a more accurate position of target from the residual images.In the process,the image block technique is used to improve the efficiency of the algorithm.Finally,three typical series of IR video were selected to verify the performance of the algorithm.The computer simulations show that the presented algorithm has more advantages in the detection accuracy,robustness,and calculation efficiency.