Abstract: In order to produce super-slim (Ø5.3 mm) combined filter rod, the key parts including raw filter rod cutting, conveying, combining and forming in YL23C filter rod combiner were optimized and modified. The key parameters of each component were determined via dynamic simulation and orthogonal experiment, and followed by practical running test. The results showed that: 1) Under the prerequisite of keeping the specification and performance of original YL23C filter rod combiner unchanged, the improved combiner could complete raw filter rod cutting and combining accurately and produce super-slim (Ø5.3 mm) combined filter rods successfully. 2) The efficiency of the combiner reached 89.27%, and the qualified rate of combined filter rod was up to 100%. The circumference of tested samples ranged from 16.63 to 16.79 mm with the roundness≤0.33 mm. The modified YL23C filter rod combiner could be switched between super-slim and normal filter rod production.