The invention relates to an identical time scale-based AGC and AVC coordination control method. The method includes the following steps of: establishing a multi-layer AGC and AVC coordination control system; realizing economic operation of a power grid; and correcting and controlling active power and reactive power of the power grid in real time. According to the method in the invention, the problem that AGC and AVC independent control can mutually affect a control effect can be solved; an interaction mechanism between an AGC and an AVC can be researched; a time scale being suitable for the AGC and AVC coordination control can be analyzed; an AGC and AVC coordination control model which is based on the identical time scale and considers the interaction mechanism between the active power and the reactive power, is provided; the conventional control method is improved; the AGC and AVC coordination optimized control can be achieved; adjustable resources and the control freedom degree of the system can be fully utilized; and the safety, the economy and the power quality of power grid operation can be improved to the greatest extent.