A sheet-handling apparatus with a detecting device includes a casing, a plurality of entrance rollers located in the casing, an image collector arranged at one side of the casing, a plurality of middle reflectors and side reflectors. A paper path is formed between the entrance rollers, the paper path includes a middle path and two side paths arranged in the sides of the middle path. The image collector includes an illuminant and an image sensor. The middle reflectors are fixed in the casing and at the other side of the paper path and face to the middle path. The side reflectors are arranged at the side of the middle reflectors. The invention can monitor a paper when it is stuck in the paper path, and the manufacture cost of the invention is reduced.