Infrared small target detection under complicated backgrounds is a key technology and a hot research in the infrared early warning system,infrared search and tracking system,etc. For dim target detection in infrared images,an infrared small target detection method was proposed based on visual contrast mechanism. Firstly,the saliency maps of the targets were calculated by the weighted Gaussian difference method. Then regions of interest were obtained by adjust parameters of fuzzy control. Finally,the contrast between regions of interest and surrounding regions was analyzed to obtain the true targets. The experimental results show that the method has the higher detection rate and lower false alarm rate,and it is an efficient infrared small target detection method.