Abstract: For the automatic pruning of the standing trees by pruning robot,the automatic measuring of trunk curvature of standing tree is a key step.According to the characteristics of digital image of standing tree,this paper puts forward a computer vision-based automatic measuring method for trunk curvature of standing tree.The method includes four steps:the tree trunk image is detected by threshold segmentation;the edge of tree trunk is detected by Laplacian operator based on the tree trunk image filtered by median filtering method;the edge image of tree trunk is thinned based on the mathematical morphology;the last step is to fit the curve and compute the tree trunk curvature automatically.The experimental results indicate that the method is available for getting accurate tree trunk curvature.