The peak-climbing algorithm in two aspects histogram compression and the two merging based on class when it is applied to high-resolution image segmentation to achieve the tree crown extraction improved peak-climbing algorithm was simulation with programing on Matlab. In order to verify the reliability of the peak-climbing algorithm on high-resolution image tree crown segmentation, QuickBird image to extract individual tree crown and analyze the precision of its area. The study result that the test sample accuracy could more than 85% using the improved and no much differences comparing with the visual interpretation. Thus this improved peak climbing algorithm meets the application requirements