A　method　of　workpiece　recognition　and　location　by　Hu　moment　invariants　based　on　Open　Source　Computer　Vision(Opencv)　is　presented　in　this　paper.　Firstly,　the　methods　of　image　preprocessing　including　image　graying,　mean　filter,　image　binaryzation　by　adaptive　threshold　segmentation　are　used.　Then,　we　extract　the　contours　from　the　binary　image.　Finally,　we　can　identify　the　object　workpiece　by　matching　the　extracted　contours　with　the　object　contour　from　the　template　image　by　Hu　moment　invariants.　At　the　same　time,　the　method　of　confirming　the　workpiece　position　and　direction　is　put　forward.　Experimental　results　show　that　the　proposed　method　can　recognize　the　target　workpiece　and　locate　the　position　effectively.　The　used　algorithms　are　simple　and　fast　in　operation.