The invention belongs to the field of excavators, and particularly relates to an all-electric servo excavator. The all-electric servo excavator comprises an operation mechanism, a swing mechanism and a travelling mechanism. The swing mechanism is rotatably arranged on the travelling mechanism relative to the travelling mechanism. The operation mechanism is hinged on the swing mechanism. The operation mechanism, the swing mechanism and the travelling mechanism are driven by an independent servo motor respectively. The swing mechanism is provided with a control cabinet for providing electric power for each servo motor, and all the servo motor are electrically connected with the control cabinet. According to the invention, an oil cylinder, a hydraulic motor and a hydraulic system of an existing excavator are all removed, the servo motors are used as power sources, the servo motors are matched with a lead screw mechanism and a gear mechanism for driving, the intermediate conversion process of energy is reduced, and the energy is effectively saved. According to the invention, no engine is needed, so pollution and noise are reduced.