Detecting targets from infrared cloud background is a typical application of infrared imaging techniques. In order to detect small targets from infrared cloud background, the background properties were analyzed, the infrared background model was built, and an adaptive background suppression algorithm based on Wiener filter was put forword. After getting rid of the fake targets and targets segmentation, the targets were detected and tracked. Experiments were done in infrared cloud background containing simulated targets. The experimental results show that this algorithm can effectively detect targets from infrared cloud background image sequences whose SNR equal to 2.0.