A scanner comprising a shell with a rut, and a lens arm matching the shape of rut connected with the shell through a revolving shaft. The scanner makes a 180 degree rotation orbiting with the revolving shaft. Lens arm and shell are vertical when in use, resembling the expansion structure of “7.” A flexible pole is retracted when out of use, and the lens arm is folded into the rut of shell. The lens arm and flexible pole are connected by metal revolving shaft as a connecting part, both of which can be set up in the shell to avoid the horizontal bar drooping or being upswept.