To provide the traverse device for a thread winder, capable of surely unwinding a thread from one side traverse guide, and delivering the thread to another traverse guide.

In a traverse device T for a thread winder equipped with traverse guides b1 and u1 running in reverse directions with each other, and alternately engaging threads (y) with each other to traverse; the following are provided thread delivering means c1 and c2: for alternately delivering the thread (y) from one side traverse guides b1 and u1 to another side traverse guides u1 and b1, and an auxiliary unwinding means d1 and d2: for assisting the unwinding of the thread (y) from the traverse guides b1 and u1 with which the thread (y) is engaged.