Abstract: In order to explore the effects of picker roller speed on cut tobacco structure and cigarette physical indexes during demi-slim cigarette making at various cut tobacco flow rates, after modifying the picker roller transmission device in ZJ17 filter cigarette maker to individual drive with stepless speed change, cigarettes with a circumference of 20 mm were studied and the structural distribution and characteristic dimensions of break-out rods and recycled excess tobacco, rejection rate of loose ends, cigarette routine physical indexes, tobacco loss from cigarette end, and dust content were analyzed during the maing process of demi-slim cigarettes at cut tobacco flow rates of 2 600, 3 100, and 3 600 g/min and seven different picker roller speeds (200, 400, 600, 800, 1 000, 1 200, and 1 400 r/min). The results showed that: 1) Flow rate and picker roller speed significantly affected the mass fraction of cut tobacco in the (4.75×4.75) mm and above mesh layers and the (1.00×1.00) mm and below mesh layers, while their effects in the (3.35×3.35) mm and (2.50×2.50) mm mesh layers were relatively small. 2) Different cut tobacco flow rates resulted in varying degrees of influence of picker roller speed on cut tobacco structure and filter cigarette making quality. 3) With increasing flow rate and picker roller speed, the characteristic dimensions of break-out rods and recycled excess tobacco decreased by 10% and 13%, respectively. The rejection rates of loose ends, dust content and tobacco loss from cigarette end showed upward trends, the standard deviation of cigarette quality indexes showed a decreasing trend, while other physical indexes did not change significantly. 4) At medium and low flow rates, picker roller speed of 1 000 r/min was appropriate, while at high flow rate, a picker roller speed of 600 r/min was more appropriate. This study provides references for similar research on demi-slim cigarettes with other circumferences.