The invention relates to a fingertip quick detecting method based on infrared videos. The method comprises the following steps of obtaining current infrared images, and conducting binarization processing on the images to obtain the position of a fingertip; storing the position of the fingertip, and determining a searching range according to the position of the fingertip; cutting out partial imagesin a corresponding area in the next frame of images according to the searching range of the current frame to obtain subgraphs; conducting binarization processing on the subgraphs; detecting connecteddomains for the graphs which are subjected to binarization processing, and regarding the connected domain with the largest area as a candidate area corresponding to the fingertip; analyzing the sizeand the shape of the candidate area to complete sifting of the position of the fingertip; through comparison of the similarity of the previous frame and the next frame, determining the fingertip area;calculating the average values of coordinate points corresponding to frame images in the fingertip area to obtain the center position of the fingertip. By means of the fingertip quick detecting method based on the infrared videos, the information of the precious frame of images is fully utilized, the position of the fingertip of the current frame is searched around the position of the fingertip in the previous frame of images, thus the accuracy of detecting the fingertip is improved, and the speed of detecting the fingertip is increased.