Abstract: An endoscope system and its corresponding image analysis methods are proposed to implement the assembly quality control of a kind of Interferometric Fiber Optic Gyroscope (IFOG). Two industrial endoscopes with diameter of 1mm and 2.4 mm are utilized to capture the inner images and the video of IFOG. A movement control platform is used to tune the attitude of endoscope system. Some image enhancement methods and image feature analysis techniques, such as the db4 wavelet enhancement technique, the Gray Level Co-occurrence Matrix (GLCM) feature analysis method and the geometry shape features, etc. are all employed to improve the imaging output quality of endoscope system. By using the proposed endoscope system, some assembly quality problems such as the remainder particles, the broken fibers, or the improper gluing, etc. can all be observed and identified conveniently.