Method for automatically controlling plate shape of continuous annealing leveling mill based on stability index

The invention relates to the field of slab band cold rolling post-treatment, in particular to a method for automatically controlling a plate shape of a continuous annealing leveling mill. A method for automatically controlling a plate shape of a continuous annealing leveling mill based on a stability index is characterized in that the method comprises the following steps of measuring data of an actually measured plate shape with a plate shape measuring roll, obtaining primary and secondary plate shape deviation coefficients alpha 1 and alpha 2; obtaining the basic parameters of a continuous annealing leveling mill through a test; firstly calculating the obtained basic gain coefficient and a stability index, and then calculating the gain coefficient, and finally multiplying the gain coefficient with the plate shape deviation coefficients, obtaining the adjustment quantity of a plate shape executive mechanism of the continuous annealing leveling mill. With the adoption of the method provided by the invention, the gain coefficient is optimized on-line with the change of the plate shape deviation; the stability index is defined in a certain value range, so that the rolling stability of the continuous annealing leveling mill can be ensured and the plate shape quality of the band steel can be improved.