The invention provides a coordination optimization method and system for a real-time power generation plan, and the method comprises the steps of obtaining the power vacancy of a secondary regional power grid, and calculating the standby capacity which can be safely called by the secondary regional power grid; when the vacancy of the power of the second-level regional power grid is greater than the standby capacity which can be safely called by the second-level regional power grid, adjusting the second-level regional power grid dispatching management unit to generate power by establishing a second-level regional real-time power generation optimization plan; and if the power generation amount of the second-level regional power grid dispatching management unit is not enough to make up the power shortage of the second-level regional power grid, establishing a first-level regional power grid real-time power generation optimization plan by establishing a second-level optimization method, and adjusting the first-level regional power grid dispatching management unit to generate power. The method is suitable for the design of a national provincial integrated adjustment object after large-scale power loss, the active power of the power grid is rapidly adjusted through scheduling of all levels, and the influence caused by high-power loss is eliminated.