This paper presents an automatic detection system for aeronautic rivets based on image recognition. The working process and principle of the system are introduced and the hardware components of the system are given. Then, based on the analysis of evaluation function of image definition captured by CCD camera, an autofocusing method which can be applied in different rivets detection is proposed. Finally, through the analysis of image filter processing and the verification of edge-detection algorithm, the scheme from edgedetection of rivets images to feature extraction is established and the main function interfaces of the system are designed.