Side Settings are driven by oil cylinder lever linkage, clamping positioning device of clamping muffler is set in the opposite on each side of the bed there are oil cylinder, piston rod, the component of fetal head. When work, the piston rod from certain depth to press the partition into muffler on both ends of the muffler, welding position. The equipment is not only accurate positioning, high production efficiency, and simple structure, easy to use.