The invention relates to a device bringing convenience to document taking by a shop assistant. According to the device, the shop assistant can conveniently find payment bills of corresponding clients. A supporting rod is arranged at the top of a base, the upper portion of the supporting rod is sleeved with a movable rod, a rack is hinged to the upper portion of the movable rod, and a locking assembly is arranged between the rack and the movable rod; a first sliding rail and a second sliding rail are arranged in an inner cavity of the rack, the two ends of a transverse beam are connected with the tops of the first sliding rail and the second sliding rail respectively in a sliding manner, and a first motor for driving the transverse beam to move is arranged in the first sliding rail; a first sliding block is installed at the top of the transverse beam in a sliding manner, and a second motor is arranged at the bottom of the first sliding block; and a second sliding block is installed at the top of the first sliding block in a sliding manner, and a third motor drives the second sliding block to slide. A storage box is arranged at the top of the rack, a plurality of first bill boxes arranged in a matrix form are arranged at the top of the storage box, and second bill boxes are placed on the first bill boxes. By means of the device, the payment bills can be conveniently taken, and the manual labor of a person is relieved.