Abstract: As the background of Datong Second Power Plant Third Project, to satisfy the “Two Documents” of North China Grid Company Limited, the optimization of coordinated control system under Automatic Generation Control(AGC) Mode for Supercritical Generation Unit is investgated. The differential signal is added to turbine master, so the turbine can response to the change of load quickly; with revising the load rate, while the condition for load and press alters, the speed is improved; the keeping strategy is used in the press setting to avoid the pressure up and down; the water\|fuel ratio and pressure deviation are introduced to the boiler master feed\|forward, and decrease the response time of boiler; the overheating adjustment is configured in the feed water system, benefitting for the pressure and water. Comparing the data before and after, it is obvious that the AGC index of unit have a great improvment. A certain of compensation may be received because of the optimization that improves the control ability of CCS under AGC, adapting to the Two Documents.