The invention relates to a multifunctional combined clamp for a vertical milling machine. A milling cutter box is arranged above a workbench top of a machine tool. A driving mechanism is arranged in the milling cutter box. A milling cutter is arranged below the milling cutter box. A vertical clamp body is mounted on the portion, on the transverse side of the milling cutter, of the workbench face of the machine tool. A horizontal clamp body is mounted on the portion, on the other transverse side of the milling cutter, of the workbench top of the machine tool. The vertical clamp body and the horizontal clamp body can be used separately and can also be combined for jointly clamping long-tube-shaped workpieces, and multiple functions are achieved. The multifunctional combined clamp is simple in structure, convenient to operate, low in cost, reliable and durable and has high clamping force, the processing safety is improved, the stability is high, and the accuracy of the processing positions of the workpieces is guaranteed effectively, and the processing quality and the processing efficiency are improved.