A double-side scanning mechanism for capturing images of a paper having two pages includes a second transparent element disposed corresponding to an outer side of a first transparent element and parallel to the first transparent element. A paper conveying device conveys a paper to pass between the first and the second transparent elements with a first page facing the first transparent element. The paper is flipped and passes over the outer side of the second transparent element with a second page facing the second transparent element. An image scanning module is disposed corresponding to an inner side of the first transparent element, for capturing the image of the first page when the paper passes between the first and the second transparent elements, and capturing the image of the second page when the paper passes over an outer side of the second transparent element.