The invention discloses an electric-arc furnace which comprises a secondary smoke exhaust hood (3), an electrode (4), an electrode small furnace cover (5), an electric-arc furnace cover (8) and a hearth. The secondary smoke exhaust hood (3) is located outside the hearth, and the electrode (4), the electrode small furnace cover (5) and the electric-arc furnace cover (8) are sequentially arranged ina sleeving mode from inside to outside. The secondary smoke exhaust hood (3) is of a cylindrical structure, one end of the secondary smoke exhaust hood (3) is provided with an inlet (31) and an electrode installing opening (32), and the other end of the secondary smoke exhaust hood (3) is provided with an outlet (33). The small furnace cover (5) is sleeved with the inlet (31) of the secondary smoke exhaust hood (3), and the electrode (4) penetrates through the electrode mounting opening (32) of the secondary smoke exhaust hood (3). The situations that in the electric furnace steel making process, air outside the furnace is prevented from entering the furnace from an electrode hole in the electric furnace cover, and smoke in the furnace is prevented from outwards diffusing from the electrode hole are achieved, so that free lifting of the electrode in the smelting process is not influenced while the electrode hole is closed.