The invention discloses an electric arc adding and milling device belonging to the technical field of electric arc adding. The electric arc adding and milling device comprises an electric arc adding unit and a milling unit, wherein the milling unit comprises a milling head; the milling unit is connected with the electric arc adding unit; and the electric arc adding unit comprises a welding gun, a supporting plate, a slide block, a fixing groove, a fixing plate, a stepping motor and a lead screw, wherein one end of the welding gun is fixed together with the slide block, the other end of the welding gun passes through a through hole of the supporting plate, both the supporting plate and the fixing plate are fixed together with the stepping motor, the fixing groove is fixed together with the fixing plate, an output shaft of the stepping motor is connected with the lead screw, and the lead screw passes through a threaded through hole formed in the slide block. The electric arc adding and milling device can be used for realizing additive manufacturing and cutting at one step, so that workpieces are more precisely machined, and the using requirement is met.