The precision of automatic generation control(AGC) and load curve implementation is an important factor affecting power network frequency and evaluation of control performance standard(CPS). A new performance evaluation method for generators in directly dispatched power plant is proposed, in which the automatic data acquisition model is used to scientifically analyze the operation of the generators and the interior coordinated control model is adopted to realize the tracking and evaluation of AGC and implementation of load curves, thus realizing the effective management to the power plants. Combining the real conditions of Guangdong power grid, a performance evaluation method for generators in directly dispatched power plant and suitable to Guangdong power grid is put forward with its feasibility verified by practical application results.