Abstract: To overcome the problems of breaking, overlapping and low recognition accuracy of the power line extraction from aerial image, a power line extraction algorithm based on improved Hough transform is proposed. The aerial image was preprocessed by grayscale and the power line edge was identified through Canny algorithm. The background noise of the edge image was reduced by removing small connected region. The single-line response criterion was satisfied by improving the judgment range of the maximum value in the parameter space of the Hough transform. The experimental results indicate that the improved algorithm can extract power line completely with high accuracy and good noise immunity compared with LSD, EDLines and traditional Hough transform.