The invention provides a high-voltage cable T-shaped plug connector dismantling device and relates to the technical field of electric power system auxiliary tools. The high-voltage cable T-shaped plugconnector dismantling device comprises a T-shaped fixing assembly. The T-shaped fixing assembly comprises a first fixing part and a second fixing part. The second fixing part comprises a first transverse half sleeve and a second vertical half sleeve which are arranged perpendicularly. A first transverse half sleeve and a second transverse half sleeve are closed to form a transverse sleeve. The first vertical half sleeve and the second vertical half sleeve are closed to form a vertical sleeve. A fastening assembly is arranged between the transverse sleeve and the vertical sleeve. The transverse sleeve is provided with a torsion bar. In the actual operation process, the structure of the T-shaped fixing assembly is matched with the structure of a T-shaped plug connector; the T-shaped plug connector just needs to be wrapped in a pipe cavity of the T-shaped fixing assembly; the torsion bar is twisted so as to be stressed uniformly, and then the T-shaped plug connector can be pulled out easily. An external insulator of the T-shaped plug connector is protected against damage in the pull-out process.