The invention relates to a steering column lower mounting support sub-assembly welding clamp of an automobile instrument board. The steering column lower mounting support sub-assembly welding clamp comprises a clamping table, rectangular holes are symmetrically formed in the left side and the right side of the middle portion of the clamping table, and a steering column lower mounting support sub-assembly clamping frame is arranged on the rear middle portion of the clamping table. The steering column lower mounting support sub-assembly clamping frame is divided into a left steering column lower mounting support sub-assembly clamping frame portion and a right steering column lower mounting support sub-assembly clamping frame portion which are symmetric about the central axis of the clamping table. The left steering column lower mounting support sub-assembly clamping frame portion comprises a middle left support. A middle left connecting frame is fixed to the rear side of the middle left support. A front middle left ejector block is arranged at the upper right end of the middle left connecting frame. An inclined face is arranged on the upper end face of the front middle left ejector block. The clamping stability and accuracy of the clamp are increased through a middle left ejector rod, welding quality of clamped parts can be improved, the position of the clamp can be adjusted conveniently through gaskets of all types, a middle left air cylinder replaces manpower for clamping, and the clamping efficiency is improved.