The aim of this work was to study the algorithm of film control method for wrapping machine, in order to solve the control problem of constant on variable diameter. A novel servo driven film feeding system was designed, the tension of which could be adjusted and switched freely, and a novel film control method was proposed, which tuned film feeding speed automatically with the variable diameter, so as to ensure the film feeding amount and realize control of feeding tension and speed. As a result, tension could be adjusted and switched freely, and both the film feeding speed and amount could meet the requirements. The practical application showed that the equipment was reliable. It effectively improved the production efficiency and reduced labor intensity.