Abstract: In order to feed the knife blade at a consistent rate, and thereby to rationalize the wear of knife blade and grind wheel, the knife feed mechanism in tobacco cutter SD5 was modified. The slide block groove on the revolving body is replaced by a spindle, the slide block is fixed on the revolving body and rotates along with the pin shaft. Cutting a slide block groove on the feed rod, the sliding of the slide block in the groove and drives the revolving body to rotate further drive the blade pusher to complete a knife feeding cycle with a constant feeding rate. Two SD504 tobacco cutters were modified and tested in Qingdao Cigarette Factory. The results showed that the average working life of knife blade and grind wheel prolonged by 31.2% and 7.2% respectively. This technology provides a support for promoting the production stability of SD5 series tobacco cutters.