The utility model discloses an offshore oil high temperature voltol oil gas well cover miller utensil, mill a section of thick bamboo and establish the tube -shape milling shoe that mills bobbin base portion at the cover including the cover, the lower extreme of tube -shape milling shoe distributes along the periphery and has four downwardly extending's arch, forms wavy structure, the internal surface and the bottom distribution of tube -shape milling shoe have the tooth of milling, the internal and external surface of tube -shape milling shoe distributes respectively along circumference to be had four inside arcs to wash clear and coherent groove and four outside arcs to wash clear and coherent groove, and clear and coherent upper end downwardly extending by the tube -shape milling shoe to the lower extreme department of tube -shape milling shoe is washed to inside arc, the bottom surface of tube -shape milling shoe prolong radial outside extend and wash clear and coherent groove with outside arc communicate. The milling shoe only mills the tooth at internal surface and bottom distribution cover, reduces the cover process of milling and damages the sheathed tube, has adopted inside and outside arc to rinse logical groove to water jacket intercommunication in making is when increase circulation flow surface is long -pending, for the clearance iron fillings provide mechanical ability of carrying.