The invention discloses a method for positioning the inter-turn insulation defect of a dry hollow reactor. The method comprises the following steps of: 1, establishing a circuit formed by overlapping a power frequency circuit and a high-frequency pulse oscillation circuit, wherein the power frequency circuit mainly comprises a second switch, a blocking inductor, a compensation capacitor and an alternating current power supply, and the high-frequency pulse oscillation circuit mainly comprises a discharge sphere gap, a first switch, a charging capacitor and a direct current power supply; 2, connecting one end of the dry hollow reactor between the first and second switches, and connecting the other end of the dry hollow reactor between the charging capacitor and the compensation capacitor; and 3, turning off the second switch and turning on the first switch to connect the dry hollow reactor to the high-frequency pulse oscillation circuit, judging whether the dry hollow reactor has the inter-turn insulation defect or not, and if the dry hollow reactor has the inter-turn insulation defect, performing steps 4 to 6, sequentially judging whether the inter-turn insulation defect is metallic breakdown, low-resistance breakdown and high-resistance breakdown, and positioning the inter-turn insulation defect according to different defect properties.