The invention provides a pay-off device and method. The pay-off device comprises a first arching and a plurality of first laser transmitters, wherein the first arching has an outer contour which is the same as that of a target tunnel and is arranged at the outer side of an excavation section; the first laser transmitters are arranged on the first arching at intervals and are used for transmittingfirst laser to the excavation section to form a projection of the contour of the target tunnel. The pay-off device provided by the invention is simple to manufacture and measurement pay-off operationis convenient and has small working amount and high efficiency.