Summary: This paper studies the problem of optimal control of the b-family equation. Result existence and uniqueness of weak solution in the interval to the b-family equation. According to variational inequality, optimal control theories and distributed parameter system control theories, it is proved that in the special Banach space, the norm of solution is related to the control item and initial value. The optimal control of the \(b\)-family equation under boundary condition is given in \(L^2\) space, and the existence of optimal solution is proved.