Traditional target detection methods cannot meet the demand of fast and accurate detection while the infrared tracking and aiming system moves. Meanwhile，infrared smoke debases imaging quality，and reduces the target detection precision. A fast method of infrared moving target detection in smoke environment is proposed. Firstly FAST feature points of two frame infrared image are rapidly extracted，and the background is matched by using improved binary BRIEF feature description，the global moving parameters are estimated with RANSAC，and the target is detected with inter-frame difference algorithm. Experiment shows that the algorithm can reduce the effect of smoke on motion compensation，detect moving target quickly and accurately，and has strong robustness for smoke interference and motion background.