The invention discloses a composite welding clamp for a lower connecting plate of a driver' seat of an automobile and relates to the technical field of automobile manufacturing. The composite welding clamp comprises a bottom plate, a left sub-base and a right sub-base. The left sub-base and the right sub-base are arranged on the bottom plate. The sub-bases are each provided with a welding clamp body. Each welding clamp body comprises a clamping device, a locating device, an adjusting device and a control switch for controlling the clamping device. According to the composite welding clamp, the problems that an existing lower connecting plate component of the driver' seat of the automobile is low in production efficiency, unstable in quality and high in production cost can be solved.