D reconstruction is a digital technology used to acquire both three-dimensional geometric and texture information about cultural relics, and is of great significance for the conservation of cultural relics, establishment of digital archives, archaeological research, exhibition and mobile digital museum construction. This technique is of use for the study of immovable painted grotto sculptures. Such a sculpture is influenced by acquisition space and is rich in texture information. Existing 3D reconstruction methods cannot recover the exact color information on the surface of cultural relics while maintaining high reconstruction precision. Using the FOTOMOULD 3D reconstruction system, with dual-camera structured light, a 3D reconstruction of a painted Bodhisattva in Cave No.45 of Mogao Grottoes was carried out, yielding high-precision geometric information as well as information on color, texture and other details.