小肠肠道发病原因隐匿并且小肠存在大量褶皱，大景深光学系统有利于在诊断过程中获得更多的病理信息，而目前市面上的胶囊内窥镜光学系统景深较小。所提胶囊内窥镜光学系统在保证一定分辨率的同时，还可在7~100 mm大景深范围内有效成像。该系统视场角为100°，F数为5，在全视场范围内调制传递函数均大于0.35（在125 lp/mm频率处），在与之搭配的OV9734成像芯片上能够满足成像要求。并对该光学系统进行了公差分析，结果表明其在可加工范围内能满足常规生产与装调。

The pathogenesis of the small intestine, with several folds, is hidden. Generally, optical systems with a large depth of field (DOF) are conducive to obtaining abundant pathological information during diagnosis. However, current capsule endoscope optical systems that are available in the market have a small DOF. In this study, we propose a capsule endoscope optical system that can effectively produce images in the range of 7?100 mm DOF while ensuring a certain resolution. The field of view (FOV) angle of the proposed system is 100°. Additionally, its F-number is 5 and the modulation transfer function is greater than 0.35 (at 125 lp/mm frequency) in the full FOV, thereby meeting the imaging requirements of the matched OV9734 imaging chip. Furthermore, the tolerance analysis of this optical system shows that it can satisfy the requirements of conventional production and assembly within the machinability range.