Abstract: In new type filter rod combiner, rod overlapping may occur sometimes during rod transferring due to a few small flaws in transfer drum design, which results in machine shutdown failures. By referring to the structure of transfer drum in imported high speed (500 m/min and 600 m/min) filter rod combiner, it was found that the optimal over-running rate t should be in the range of 0.03-0.08, and angle-differential rate w in the range of 0.15-0.35. These design data were introduced to and verified in the transfer drum in type ZL41 (400 m/min) filter rod combiner. The speed of the tape was also adjusted to match that of the transfer drum. After improvement, the rod-overlapping phenomenon was basically eliminated, and the machine efficiency was raised.