The invention discloses an aerial image-based power transmission line detection method. The method comprises the following steps of firstly obtaining two-dimensional enhanced matrix eigenvalue and eigenvector corresponding to each pixel point by utilizing a Hessian matrix, and according to relationships between eigenvalues and eigenvectors, obtaining edge information of an aerial image; secondly according to a power transmission line distribution characteristic in the aerial image, proposing a simplified aerial image power transmission line distribution model; and performing block segmentation on the aerial image, obtaining a boundary of a power transmission line region, and obtaining a region segmentation coefficient; thirdly detecting a power transmission line by applying a Hough transform detection method to the image; and finally performing judgment by using a line spacing and a power transmission line slope, removing line segments not meeting the requirements, and reserving line segments meeting the requirements as a real power transmission line. The method is high in detection speed and high in detection precision, and can detect real power transmission line information in the aerial image with a complex background; by adopting the method, the problems of long consumed time and slow detection progress are solved; and the detection and identification rate of a power transmission line target in the aerial image is effectively increased.