A method for image correction and a scanner using the same are provided. The scanner includes an image sensor and an automatic document feeder. The automatic document feeder has a paperweight mechanism. The method includes marking a first and a second characteristic regions on the paperweight mechanism; using the image sensor to search the two black characteristic regions to define a scan line; when the document is to be scanned, moving the image sensor to a position corresponding to the scan line, and starting to scan the document in order to obtain a scanned image; identifying the scanned image to obtain two position information associated with the two black characteristic regions; calculating a tilt angle of the scanned image according to a distance between the two black characteristic regions and the two location information; and finally correcting the scanned image angle according to the tilt angle.