Abstract: This paper introduces the structure of an electric control system of a high-speed machine of aluminum foil-doubler. The entry reel adopts linear velocity control system, while two pay-off reel adopt tension control system. According to the characteristics of small tension of the aluminum foil, main driving adopts the reversible D. C. motor of SCR supply with circulating current control. The linear velocity control system adopts non-independent variable field system. The tension system adopts indirect control system. During the system design some special control elements are used, and the system adopts serial-parallel correcting devices for improving dynamic indices.