The invention discloses a 10kV cable channel coverage type external damage warning instrument, which comprises a transformer substation, a ring main unit and a T-junction box, and is characterized inthat the transformer substation, the ring main unit and the T-junction box are connected through cables, and the T-junction box is electrically connected with a warning system; the invention has the following beneficial effects: at present, the technical scheme is effectively implemented, the anti-external-damage warning instrument completely exerts the early warning function; short messages are successfully sent for 229 times; external force damage accidents are greatly reduced; taking single cable accident for calculation, every time when an accident is reduced, the cost of repairing a manual vehicle can be saved by 1000 yuan, the cost of replacing cable head accessories can be saved by 1000 yuan, the power failure time can be averagely reduced by 8 h, various power failure losses can bereduced by 3000 yuan in total, and 5000 yuan can be saved through single successful alarm. And after 229 times of successful alarming, 114.5 thousand yuan is saved in total.