The invention provides a grid emergency power support method employing cooperation of multiple pumped-storage power stations. The grid emergency power support method includes starting emergency support according to an emergency support starting preparation command, an emergency support starting command and an emergency support target power command which are issued by a main station to the power stations; implementing the emergency support, to be specific, according to a load planning curve and the emergency support target power command, a power station grouping controlling system starts and stops the units and regulates the load; quitting the emergency support, to be specific, the main station issues an emergency support quitting starting command to the power stations, and the power stations start and stop the units and control the load; in the case that the emergency support target power reduces to 0, the main station issues an emergency support quitting completion command, and the emergency support process is finished. The grid emergency power support method has the advantages that based on the emergency reserve capability and the local grouping controlling functions of the pumped-storage power stations, the remote automatic pump cutting and filling function and the automatic generator unit starting function are achieved, the emergency support power is provided, and the grid frequency is restored.