Abstract: By analyzing the technical progress of auto-control system for unwinding tension of warp sheets from sizing beam in re-beaming machine,a new auto-control system is developed so as to ensure the tension of unwinding warp yarns even.A comparison is made between the old and new control systems in terms of technological characteristics.This new system quickly senses the change of unwinding tension of silk sheets from sizing beam by strain gauge sensor,uses frequency converting motors to apply the resistant or driving functions to the sizing beam and control the rotating velocity of sizing beam so that the unwinding tension can be kept at a preset value.This new system is also suitable for re-beaming of warp yarns for union fabrics of multi-fibers.The system demonstrates well operational performance when applied to a digital filament re-beaming machine with two accompanying unites.