The invention provides a method for designing the heat storage capacity and the heating power of an electric heating system, comprising the steps of determining the daily wind curtailment power of a wind farm in the heat supply period, designing the heat supply power and the heat storage capacity of the electric heating system, and designing the heating power of the electric heating system. The heating power of the electric heating system is designed according to the wind curtailment power curve of the wind farm, and abandoned wind power can be utilized to the maximum; the heat storage capacity of the electric heating system designed by the invention takes into consideration the scenario with least wind curtailment of the wind farm, and the quality of heat supply can be ensured under the condition that abandoned wind power is utilized to the maximum; and the heat storage capacity and the heating power of the electric heating system designed by the invention are minimized under the condition of ensuring the quality of heat supply, and the investment cost of the electric heating system is reduced.