Hot rolled strip steel convexity control method

A hot rolled strip steel convexity control method comprises the steps of according to original roll profiles, abrasion, thermal expansion of rollers and concrete rolling conditions (such as rolling force, plate width and plate thickness), utilizing a mathematic model to calculate plate shape setting and controlling parameters such as roll bending force and crossing angles of the rollers; after threading of a strip steel, carrying out automatic convexity control, which comprises roll bending force compensation for roller thermal convexity change, roll bending force compensation for rolling force change and actual measurement convexity feedback control; according to actual measurement strip steel convexity and target convexity, utilizing the mathematic model to carry out convexity self-learning so as to improve the setting precision of the next roll of strip steel. According to the hot rolled strip steel convexity control method, the strip steel convexity precision and the overall length convexity stability can be effectively guaranteed under the condition that deviation appears in the convexity setting or the rolling conditions drastically change.