The invention relates to an electrode steam boiler and a working method thereof. The electrode steam boiler comprises a boiler body; the upper part of the boiler body is steam storage space; boiler water is accommodated in the lower part of the boiler body; and a water feeding pipe and a main steam valve are arranged on the boiler body. The electrode steam boiler is characterized by further comprising a center cylinder arranged at the upper part of the boiler body; one part for heating of a high-voltage electrode is dipped in the water in the center cylinder; and a water circulating system is arranged between the center cylinder and the lower part of the boiler body. The water circulating system comprises a circulating water pump, a circulating pipeline, a center cylinder bottom water inlet pipe and a center cylinder water falling pipe; one end of the circulating pipeline communicates with the lower part of the boiler body, and the other end of the circulating pipeline communicates with the center cylinder bottom water inlet pipe; the circulating water pump is arranged on the circulating pipeline; and a valve is arranged on the center cylinder water falling pipe. As the steam space of the boiler is large, the water carrying rate of output steam is low, and the quality is high. The lower part of the high-voltage electrode is dipped in the water in the center cylinder, so that safety, reliability, stability and high efficiency are achieved.