To realize the prevention of an overload in the driving system for a rolling mill without restriction by a simple method in the calculation for setting each pass of a rolling schedule, which is a technique applied to the rolling mill in which the upper and lower rolls of the rolling mill are rotated at different speeds and related to a method for preventing an overload in the driving system such as a spindle of the rolling mill.

In a preventing method of an overload in the driving system of a rolling mill capable of rolling by varying the number of revolution of upper and lower rolls, the estimating calculation of TAF which is the ratio of a max. torque at the time of biting in rolling which acts on the driving system of the rolling mill to a stational torque at the time of rolling is executed from the set value of a rolling speed at the time of biting in rolling. The estimated value of the max. torque at the time of biting in rolling which is calculated based on the estimating-calculated TAF is compared with the value of the allowable torque of the driving system of the rolling mill and the rolling is executed by adjusting the set value of the rolling speed so that the estimated value of the max. torque at the time of biting in rolling is not higher than the value of the allowable torque.