The invention provides a parallel control method for high-capacity energy accumulation converters of an energy accumulation power station. The parallel control method comprises the steps that first, all electrical equipment in the energy accumulation power station is initialized; second, communication information is sent between PCS units; third, if the quantity of the communication information sent by the PCS units and the quantity of response information received by the PCS units are the same, the PCS units start to conduct grid connection; fourth, one PCS unit is determined to be used as a main machine, and the rest PCS units are slave machines; fifth, the slave machines conduct adjusting according to the output voltage of the main machine, and grid connection begins; sixth, if the slave machines do not complete grid connection within preset time, grid connection is stopped, and grid connection failure signals are sent. Compared with the prior art, according to the parallel control method for the high-capacity energy accumulation converters of the energy accumulation power station, on-line reliable parallel connection of the multiple energy accumulation converters can be achieved, and the capacity of the energy accumulation power station is expanded. The strategy of electrically free main machine seizing of the energy accumulation converters is adopted, the risk of faults caused by manually setting the main machine is avoided, and the reliability of the energy accumulation power station is improved.