Abstract: A traverse thread reeling machine wherein a thread reeling bobbin is mounted on a driven drum having a wave-shaped groove fitting a thread on the outer periphery so that the thread may be reciprocated at a predetermined period by the wave-shaped groove on the drum, light sources and photoelectric elements are provided as opposed to each other on both sides of the thread reciprocating plane so that, when the photoelectric elements have stopped sending out pulse outputs, a signal may be sent to a cutter or a drum driver to cut the thread or to stop the drum to thereby prevent a false reeling.