A three-dimensional scanning system comprising: a projection apparatus, the projection apparatus comprising: a light emission portion, configured to emit multiple rays of preset light, wherein the multiple rays of preset light correspond to multiple preset wavebands, and the multiple preset wavebands are different from each other; a light transmission portion, disposed on a transmission path of the rays of preset light, the light transmission portion includes a color grating sheet, wherein the rays of preset light is transmitted via a preset pattern on the light transmission portion to generate target light projected to a target object in the form of color-coded fringes, and the light transmission portion transmits the rays of preset light corresponding to at least two different preset wavebands, the light transmission portion is provided with multiple preset images, multiple preset images generate the color-coded fringes, and each preset image corresponds to a different preset waveband, the color-coded fringes use colors as basic elements of space coding, and the encoding of the color-coded fringes corresponds to the encoding of multiple colors pre stored by a image processing portion; a target reflector for changing the transmission path of the target light; and multiple illumination units, configured to illuminate the target object, wherein the projection apparatus is configured to project the light emitted by the multiple illumination units to the target object together with the target light reflected by the target reflector; an image collection apparatus comprising an image collection portion configured to collect multiple shadow images including the projection pattern generated by projecting the target light to the target object; and the image processing portion configured to perform data processing on the multiple shadow images by using software algorithm to obtain three-dimensional data of the target object. a light emission portion, configured to emit multiple rays of preset light, wherein the multiple rays of preset light correspond to multiple preset wavebands, and the multiple preset wavebands are different from each other; a light transmission portion, disposed on a transmission path of the rays of preset light, the light transmission portion includes a color grating sheet, wherein the rays of preset light is transmitted via a preset pattern on the light transmission portion to generate target light projected to a target object in the form of color-coded fringes, and the light transmission portion transmits the rays of preset light corresponding to at least two different preset wavebands, the light transmission portion is provided with multiple preset images, multiple preset images generate the color-coded fringes, and each preset image corresponds to a different preset waveband, the color-coded fringes use colors as basic elements of space coding, and the encoding of the color-coded fringes corresponds to the encoding of multiple colors pre stored by a image processing portion; a target reflector for changing the transmission path of the target light; and multiple illumination units, configured to illuminate the target object, wherein the projection apparatus is configured to project the light emitted by the multiple illumination units to the target object together with the target light reflected by the target reflector; an image collection apparatus comprising an image collection portion configured to collect multiple shadow images including the projection pattern generated by projecting the target light to the target object; and the image processing portion configured to perform data processing on the multiple shadow images by using software algorithm to obtain three-dimensional data of the target object.