A tension system optimization method for the rolling of ultra-thin strip steel in a tandem cold rolling mill, which relates to control equipment or methods specially suitable for metal rolling mills or their processed products, in particular to a comprehensive control of the rolling process of ultra-thin strips in a tandem cold rolling mill The tension system is optimized, using the existing equipment parameters and process parameter data of the control system of the cold tandem rolling mill, according to the entrance tensile stress, exit tensile stress, deformation resistance, rolling speed, strip width, entrance thickness, and exit tension of each rack. Thickness, work roll diameter, calculate the slip factor, thermal slip index, vibration coefficient, rolling force, rolling power of each stand under the current working conditions, realize the optimal control of the tension system through computer program control, and consider rolling stability , slipping, thermal slipping and vibration, while taking into account the reduction capacity, rolling efficiency, and the exit shape and tensile stress distribution of each stand, the exit shape of the final stand that characterizes the quality of the strip is significantly reduced, and the strip mass ratio The traditional method has been significantly improved.