Abstract: Aimed at the problems of flow fluctuation and low control accuracy at casing stage in the primary processing line, the feeder of electronic weighing belt was modified, including 1) adopting step type tobacco feeding, and adding 3 pairs of optoelectronic switches to ensure the continuity of tobacco flow; 2) adopting frequency conversion drive and speed linkage to regulate tobacco feeding speed. After improvement, the flow deviations of both lamina and casing were controlled under 5%, the accuracy of casing was increased.