Abstract: A weft controlling device for using weft as warp in a strap weaving machine has motors mounted on an assembly board and controlling rods each movably connected to a corresponding one of the motors by a controlling thread and each controlling rod having a weft hole in a distal end thereof so as to allow weft to pass through the weft hole. Springs are each mounted around a corresponding one of the controlling rods to provide a recovery force to the corresponding controlling rod. The movement of the controlling rods by the motors is able to drive the weft to a specific position for selection by the strap weaving machine.