The invention provides a tool for a sapphire ingot plane abrasion guide edge. The tool wholly comprises a base, an adjusting border, a clamping border and a fixing screw. The tool is characterized in that the base comprises a lower border and a supporting border, wherein the lower border is parallel to the horizontal plane and is provided with a linear groove, the supporting border comprises a front supporting border and a back supporting border, the front supporting border and the back supporting border are vertical to the horizontal plane, and the adjusting border is parallel to the horizontal plane and is provided with an embedding type nut; the clamping border is parallel to the horizontal plane and is provided with a threaded hole; and the fixing screw is an inner hexagonal screw. When the tool is used, the tool is placed on an orientation device, a sapphire ingot is placed on the base of the tool, the adjusting border and the clamping border are fixed through the fixing screw, the ingot is rotated to accurately position and fixedly clamp the guide edge, and the ingot is taken down from the orientation device to be placed on a horizontal shaft distance table flat grinder to start to guide edge plane abrasion. By means of the tool, the traditional technological process for the sapphire ingot plane abrasion guide edge is effectively simplified, the number of machining processes is decreased, the production efficiency is improved, use of consumables is avoided, the manufacturing cost is reduced, and the aims of energy saving and emission reduction are achieved.