In this paper, we discuss rolling regulations of hot strip mills and use mechanism models to build operation optimization problem (OOP). However, the OOP takes on the character of highly nonlinearity and coupling. It is difficult to solve the global optimal solution of OOP. To overcome this difficulty, we present the method based on GP Modeling. Because (GP) problem can be transformed into a convex optimization problem, it is guaranted that any local minimum is also a global minimum. By well-posed algebraic transformation and using characteristics of (GP), the OOP problem is approximated as a convex programming. Our numerical experiments demonstrate this method can achieve the reasonable set-points for rolling regulations.