The tool handle is the key supporting part of the static shaft shoulder process to transfer energy, it is used to fix the stirring needle, through the tool handle to transfer the spindle rotation energy to the stirring needle, drive the stirring needle rotation and material friction to generate heat, so as to plasticize the material to be welded, and then combined with the sliding forging action of the shaft shoulder to form a dense weld. According to the product support structure, the tool handle can be customized according to the product cavity structure, and the use of the static shoulder process can be realized by lengthening the tool handle (with the corresponding lengthening support cover).