The invention discloses a CAD (computer-aided design) people counting method based on FAST (features from accelerated segment test), and belongs to the field of computer vision-based people counting. The method is characterized in that after a crowd surveillance video image is subjected to filtering preprocessing, an FAST corner feature vector of a current image is obtained through a corner detection algorithm; a low-density crowd image and a high-density crowd image is divided according to the ratio of the number of feature points and the sum of pixels of the current crowd image, and foreground images of the low-density crowd image and the high-density crowd image are extracted; as for the foreground image of the low-density crowd image, the connected domain area T obtained through an erosion algorithm is taken as an FAST point, and as for the foreground image of the high-density crowd image, a neighbor domain is established for the core point of each pixel through an OPTiCS algorithm, then, the minimum reach distance from the core point of each neighbor domain to each pixel is taken as the minimum reach distance in each neighbor domain, and an FAST point vector X of the high-density crowd is constructed accordingly; a crowd evaluation model is constructed according to T, X and the distance D between a camera and the crowd; and a set training sample is taken as a test vector for performing SVM (support vector machine) training, so that the counting speed and the accuracy rate are increased.