The invention relates to a method for accurately positioning interference air film holes in electric sparking of integrally-cast linked blades. The method comprises the following steps of, step 1, adjusting XYZ three-way angles of interference holes into two-way or one-way angles; step 2, placing an integrally-cast linked blade 11 on the arc surface of a positioning table of a base 1 of a positioning device through a mounting plate on the integrally-cast linked blade 11, machining interference holes inside a pressure side of a blade A 12, and machining interference holes in a suction side of ablade B 13; step 3, measuring the cross section; step 4, carrying out coordinate system deviation compensation; step 5, tool setting; step 6, moving row electrodes to actual machining positions to confirm that a machining path has no interference; and step 7, replacing the row electrodes through assembling and disassembling precise replaceable electrode plates, and performing tool setting post-machining. According to the method, the problem of low interference air film hole positioning precision caused by the influence of the problems of profile deviation, large positioning error, electric spark process limitation of integrally-cast duplex blades is solved, the accurate positioning work of electric sparking machining of the interference air film holes of integrally-cast duplex blades of anew machine is successfully completed, and verification batch trial production is completed.