The invention provides a method for quickly detecting a human head, and the method comprises the steps: calculating a resolution image and the minimum and maximum radius images of a human head according to a calibration line; calculating edge point images and edge gradient vector images of the images; obtaining a Hough space image according to Hough voting; extracting candidate points of the human head; calculating the radius and confidence of candidate human heads, and obtaining candidate human head regions; carrying out the candidate human head regions; enabling the residual candidate human head regions to serve as human head detection regions, and outputting the residual candidate human head regions. The method achieves the quick detection of the human head, and can be used in pedestrian counting.