Abstract: Fuzzy edge images exist in non-contract width measurement of hot rolling strips based on image processing. They would result in inaccurate image edge detecting, which has a bad effect on the accuracy of width measurement. In order to accurately confirm the location of edge and eliminate the impact of fuzzy edge on the accuracy of width measurement, edge operators were developed, and a dual-template method was presented and applied based on the analysis and comparison of various operators. The new method was successfully applied to measure the width of hot rolling strips on line, and steady and exacter measuring results were gained. It was verified by experiments that the dual-template method can accurately measure the width of hot rolling strips whose images edge is fuzzy.