With regard to the contradiction between noise-smoothing capabilities and accurate positioning of image edge,which results from the existing image edge detection algorithms,a new infrared image edge detection method based on fuzzy neural network is proposed utilizing the fuzzy neural network′s learning,adaptive and fuzzy processing.We calculate basic gradient,left associated gradient and right associated gradient of each pixel in eight directions,which constitutes gradient array.The gradient arrays in eight directions are then set as input of fuzzy neural network.Finally the relatively precise infrared image edge is obtained by learning and obfuscation.Experimental results show that this method has powerful denoising capability.It can retain intact edge whose edge width is single-pixel level.That indicates the method is superior to other algorithms in dealing with infrared image edge.