Disclosed is a device and method for stacking a fuel cell stack, which enables automated accurate stacking of components constituting the fuel cell stack by using a phosphor coated thereon. Accordingly, when a membrane-electrode assembly (MEA), a separation plate, etc. are automatically stacked in sequence they are coated with phosphor at a predetermined position on each of the MEA, the separation plate, etc. A phosphor sensor is then positioned and configured to automatically determine whether or not the MEA and separator have been accurately stacked by detecting the presence of phosphor on the stacked MEA and separator plate respectively.