The invention discloses a high-voltage pothead lineation cutting positioning method. The method comprises the steps that the front end face of a positioning block at the end of a main ruler clamping jaw of a high-voltage pothead lineation cutting positioning device is made to be aligned to the end face of a high-voltage cable to be cut, an auxiliary ruler clamping ring is clamped to the external circle of the high-voltage cable, an auxiliary ruler is moved to the required lineation size L1, a first lineation cutting positioning auxiliary device is installed, the right end face of the first lineation cutting positioning auxiliary device is made to be aligned to the left end face of the auxiliary ruler, a screw is locked, and the position of the lineation position L1 is determined; the steps are operated repeatedly, and then the positions of lineation positions L2, L3, L4, L5...Ln are determined; a lineation tool is used for conducting lineation on the external circle of the high-voltage cable in sequence at last, corresponding positions of L1 to Ln sizes are determined, and materials which need to be peeled off are cut and peeled off layer by layer. The high-voltage pothead lineation cutting positioning method achieves lineation positioning at a time, the precision reaches 0.02mm, and cable sheathes, steel belt steel armors, copper shield layers, conducting shells, main cable insulation layers and the like are peeled off layer by layer according to the lineation positions.