The invention relates to an electric servo C-shaped robot welding clamp. The electric servo C-shaped robot welding clamp comprises a driving module, a protective cover, a substrate, an upper plate, a fixed electrode arm module, a movable electrode arm module, a water pipe module and a transformer module. The driving module includes a servo motor and a speed reducer; the fixed electrode arm module includes a welding clamp arm connecting bracket, an aluminum alloy welding clamp arm, a copper connecting block, a copper welding clamp arm, a fixed electrode rod and a fixed electrode cap; and the movable electrode arm module includes a movable electrode arm, a movable electrode rod, a movable electrode arm cover, a movable electrode cap, a linear guide rail, a plummer linear bearing, a ball screw and a push rod. The water pipe module includes a distributor, a water inlet pipe, a water return pipe, a fixed electrode arm water return pipe, a movable electrode arm water return pipe, a transformer water return pipe, a fixed electrode arm water inlet pipe, a transformer water inlet pipe, a movable electrode arm water inlet pipe and a water pipe mounting bracket; and the transformer module includes a transformer, a copper bar 1, a copper bar 2, a copper bar 3 and a soft copper bar. The electric servo C-shaped robot welding clamp adopts a modular servo technology, and is precise in control.