The invention discloses a spatial large view field, superwide spectral band and multispectral imaging optical system, which comprises a switching reflector, a main optical off-axis three-reflector system, a medium- and short-wave focus-free relaying optical system and a long-wave focus-free relaying optical system, wherein a radiation light beam of an imaging target enters from the switching reflector, and is divided into light rays in three channels, namely a visible multispectral channel, a short-wave/medium-wave channel and a long-wave infrared channel, by color division sheets after passing through the main optical off-axis three-reflector system; the light ray in the visible multispectral channel is reflected by the first color division sheet, and then full-color multispectral imaging is realized through a five-color device; the light rays in the short-wave/medium-wave channel and the long-wave infrared channel are transmitted/reflected by the second color division sheet, respectively pass through the own focus-free relaying optical systems, and then are focused on a focal surface for imaging after being subdivided by filters. The spatial large view field, superwide spectral band and multispectral imaging optical system has the advantages of large view field, large relative aperture, wide spectral range, high subdivision degree, compact structure, small volume, light weight and the like; and large-range, all-day and high-resolution dynamic and stable detection can be realized.