The spatial resolution, time resolution and spectral resolution of the space remote sensing camera are improved gradually, the spectral band for observation of the camera is also extended and the multispectral observation is realized. The design of visible and infrared integrative optical system is studied based on the need of multispectral observation. The design is accomplished through calculation and an optical design software. In this design, the system focal length of the visible part is 6000 mm, F number is 11.8 and the wavelength band is 400~900 nm. The system focal length of the infrared part is 1280 mm, F number is 2.5 and the wavelength band is 3000~5000 nm. The field of view is 1.4°×0.6° for both of the systems. The visible band system and the infrared band system share the first four mirrors, the fifth is a dichroic mirror and reflects the visible light to the time delayed and integration CCD which is over the fifth mirror. The infrared light passes through the fifth mirror to the rear lens set for correction. The whole system has no color aberration, its structure is compact, and the image quality for visible and infrared is up to par.