Capturing an iris image rapidly is required for iris image acquisition embedded system. For the traditional method, an iris image must firstly pass through the quality evaluation, which is complex, so the acquisition speed is very slow. This paper described an iris acquisition embedded system, and a new capturing method. The system includes an DSP DM642, and some relevant peripherals. When an image is acquired, it is filtered by the capture-control function, if passed then be stored the image, until capturing the assigned amount. Using this method, we can rapidly capture the high quality iris images at about 0.8s, and 83% of the stored images can be used for the next procedure. At the same time, it is convenient for the user to capture.