The relationship between the rolling force and the initial thickness of the Al-Mg-Li sheet preform for thicknesses of 1.8 mm and 4.8 mm was shown for cold rolling prequenched and artificial aging. Samples with a thickness of 7.3 mm were obtained by hot rolling with cooling from the deformation temperature. Thermoanalytical support of the rolling process is carried out by the method of temperature analysis based on isothermal discrete scanning (IDS) data. It gives the connection of effort with internal temperature distributions, which have general patterns of properties, regardless of the complexity of the structure and composition of the material. The presence of periodicity and steady-state temperatures after IDS makes it possible to partition the results of the temperature scanning of the samples into sections. As a result, it is possible to improve the accuracy of estimating the effect of the initial thickness of the workpiece on the force for each of the passes during cold rolling, without correction for the thermal or technological past.