In order to make system as possible as near target value in given time according to requisite control effect,....ontrol function can be selected based on the principle of optimal control in this paper. According to maximum principle of Hamilton function, required optimal control can be obtained from the solution of the nonlinear differential equation. Reason stabilization running on interior area power grid of mining office of steady running mechanism was researched using this optimal control, and dynamic characters of the whole mining office power grid analyzed. Applying optimal control theory, steady measure can be carried into execution together in south and north grid so as to prevent the change of system from the load disturbance effectively. Finally, the example as improvement of the power grid of interior mining office illustrates that the stability of power grid is both to guarantee the security production of mine and to increase economic benefits.