With the rapid development of photoelectric detection technology, the wide use of various interference, camouflage and stealth technologies, as well as the diversity of detection and identification targets and the changing complexity of the use environment, single-spectral photoelectric detection technology is insufficient. The combination of infrared imaging detection and visible light imaging detection can improve the all-weather detection capability, anti-interference capability and target acquisition capability of the photoelectric imaging components. If the optical system of the long-wave infrared/visible dual-spectral imaging components adopts a common aperture splitter structure, each channel uses a separate optical structure and detector, it is assuredly easier to achieve, but the structure will be more complex, the volume and mass will be relatively larger, and the assembly difficulty is relatively larger. On the basis of ensuring the detection capability of the photoelectric imaging components, in order to realize the miniaturization of the long-wave infrared/visible light dual-spectral composite photoelectric imaging components, combined with the engineering application requirements, the long-wave infrared/visible light dual-spectral composite photoelectric imaging components has been successfully designed and fabricated by the modular design idea.Firstly, the optical system is designed according to the optical parameters in the technical requirements. Secondly, the electronic system is designed according to the electrical parameters in the technical requirements. Then, based on the size of optical system and circuit system, the structure is designed and realized. In this process, each part is adjusted and optimized according to the requirements of technical indicators to achieve the purpose of meeting the indicators. Finally, according to the optical, mechanical and electrical characteristics and working requirements of the composite photoelectric imaging components, the environmental adaptability design is completed. The specific design method is as follows: The optical part adopts coaxial refraction reflection type, and the detection component adopts long-wave infrared/visible light integrated movement design. The mechanical structure does not adopt the three-arm bracket with large volume and more light blocking, but fixes the visible light lens group and the planar mirror as an integral component in the center of the first infrared lens, and makes the visible light detector and the side wall of the infrared lens cylinder basically parallel. In this way, space is saved to the greatest extent, the volume is reduced, and the shading of the infrared channel is reduced.The long-wave infrared light signal is imaged to the uncooled focal plane detector through three infrared lenses including diffraction lenses. The visible light signal is focused through the visible light lens set nested in the center of the first infrared lens, reflected by the planar mirror located in the aperture center to the side of the infrared lens cylinder, and received by the CMOS detector as (Fig.4) and (Fig.8). The performance of the optical system in the long-wave infrared/visible dual-spectral composite photoelectric imaging components directly affects the detection range and target recognition accuracy of the photoelectric components. The design results of the optical part are as follows: The working wavelength of the long-wave infrared channel is 8-12 μm, F# is 0.95, the focal length is 44 mm, the field of view is 10°×8°, and the optical length is 53 mm; Visible light channel operating wavelength 0.45-0.75 μm, F# is 4.3, focal length 25 mm, field of view 7.9°×6.3°, total optical length 32 mm.The whole optical-mechanical system has been passive non-thermal design at -40-+60 ℃. The composite photoelectric imaging components have simple and compact structure, small size and light weight. The volume (length × width × height) is 62 mm×40 mm×50 mm, and the total weight is (133±3) g. The experimental results show that the composite photoelectric imaging module has good imaging performance and fully meets the design criteria.