A paper pressing device for a scanning apparatus is provided, which include a scanning module and a paper track corresponding to the scanning module, wherein the paper track is provided for a paper sheet passing through. The paper pressing device includes a film and a pressing block. The film is disposed on one side of the paper track opposite to the scanning module. The pressing block is disposed on one side of the film opposite to the scanning module and presses against the film for reducing the height of the paper track above the scanning module. When the paper sheet is passes over the scanning module, the paper pressing device presses the paper sheet for maintaining the paper sheet flat while being scanned.