現今工業都朝向自動化發展，各家工具機廠商亦致力於提升產品的品質及自動化生產的目標，刀具磨耗的情況常常會對產品的品質與自動化生產的效率產生重大影響。針對銑床的端銑刀磨耗檢測的需求，本研究希望研發一套機械視覺為基礎的線上刀具磨耗檢測方法。由於端銑刀的複數刀刃與螺旋形刀具形狀不同於一般車刀，加上金屬的反光的效應，增加的端銑刀在影像拍攝困難，本研究利用刀具影像疊圖的技術將立體的端銑刀展開成平面圖面，並使用影像處理的方法對展開後的刀具圖片進行磨耗檢測。實際以工具機機台進行切削加工，定時進行刀具影像疊圖並檢測刀具磨耗狀態，可驗證本研究發展機械視覺系統應用銑床的端銑刀於線上刀具磨耗檢測的可行性。 In recent years, the industry is developing towards automation. Various machine tool manufacturers have devoted to improving the quality of products and reaching the goal of automated production. Tool wear has a significant impact to the quality of products and automated production. Because the demand of automatic online inspection system of tool wear increases, this study try to develop a method for automatic online inspection system of tool wear based on machine vision. Since the number of teeth and the geometric shape of the end mills are different from the turning tool, end mills are more difficult to shoot in images. This study develops a method of tool stitching to expand the three-dimensional end mill into a plan view and uses the image processing method to perform wear detection on the expanded tool image. The experiment results based on the practical milling in machine tool monitor the tool wear condition at regular time. The thesis verifies the feasibility that machine vision system can be applied on the automatic online inspection of end mill.