Laser scanning and 3D printing could be used in the protection and restoration of cultural relics. Considering the limitations of the traditional digital methods of cultural relics, the non-contact and rapid acquisition of massive target surface data by laser scanning has outstanding advantages. Taking the Zhaozhou Bridge as an example, the basic technological process of using laser scanning and 3D printing technology in cultural relics preservation is elaborated, and the problem of digital information retention and accurate restoration of traditional cultural relics is solved. The special application of laser scanning and 3D printing in cultural relics preservation is studied.