In order to extract weld pool edge in wide-band laser cladding accura tely and efficiently,and eliminate the interference such as strong arc,molten metal droplets and powder spatter,a m onitoring system composed of a charge-coupled device (CCD) camera and a composi te filter is used to gather the molten pool images directly during the laser cladding.The obtained molten pool image is preprocess ed,and the appropriate threshold is selected to fit a quadratic curve as the initial contour.Assuming that the t arget region and the background region have the maximum average grayscale difference,the geometric structure informati on of the molten pool and the local statistical information of the image are used to drive the contour evoluti on,ultimately,the pool edge in wide-bond laser cladding is extracted accurately.Compared with the traditional methods,such as gray threshold, digital morphology and Chan-Vese (C-V) active contour model,the experimental r esults show that the precision and anti-interference performance of the propose d method are improved.