A new method to deal with images by computer is put forward, which is more convenient for the eyes to identify and much easier to understand. As the image edge is a basic character of image, checking it is one of the most important parts in processing the image. The traditional technique is to use the edge detection algorithm, which is to detect the gray level changes of every pixel of image in some epsilon, and to detect the image edge by using the changing regular of directional derivative. But sometimes there is uncertainty of image edge, and man can't distinguish it is the edge or not. Diagram algorithm can't solute this pivotal problem. In order to turn the fuzzy edge to be in focus and solve the problem above, this paper mentions fuzzy enhancing technique to realize image edge's being detected. Fuzzy technology is a newly rising technology used in many fields, especially in the image domain, and fuzzy enhancing technique is one important portion of the fuzzy technology. Based on this technology, this paper firstly sets the image fuzzy characteristic plane of original image, secondly proceeds the fuzzy enhancement, and then detects the edge by Sobel differential arithmetic. At the end of the paper, it realizes the histogram algorithms and the fuzzy enhancing algorithm by Visual C++. Results of the experiment show that fuzzy enhancing algorithm is a superior one in image procession.