The invention discloses withdrawal straightening winding tension acquisition method and device, and a tension control system. The method comprises the steps of acquiring the initial tension, the totallength of a steel belt and the winding length; determining the winding tension according to the initial tension, the total length of the steel belt and the winding length; when the winding length issmaller than or equal to the preset length, determining that the winding tension is equal to the initial tension; when the winding length is larger than the preset length, determining that the windingtension is reduced along with the increase of the winding length; and when the winding length reaches to the total length of the steel belt, determining that the winding tension is the preset tension. According to the withdrawal straightening winding tension acquisition method and device, and the tension control system provided by the invention, the winding tension is determined through the initial tension, the total length of the steel belt and the winding length, the acquired winding tension is correlated to the winding length, the winding efficiency can be ensured, and the probability of the occurrence of the winding collapse phenomenon during the winding process can be reduced.