The invention discloses a high-voltage electric power zero-sequence current transformer for a power transmission line. The zero-sequence current transformer comprises a base tube, a core column, a bolt, the current transformer and a plate-clamping assembly, wherein the base tube comprises a tube-pressing part and a plate-sealing part which are fixedly arranged in a relative manner; a limiting sliding hole and threading holes are formed in the plate-sealing part; crimping lug bosses are arranged on the inner wall of the tube-pressing part; a conical crimping surface is arranged on the outer circumference wall of the core column; the plate-clamping assembly comprises wire-clamping plates; a guiding sliding table is arranged on the inner wall of each wire-clamping plate; a guiding sliding groove is formed in each wire-clamping plate; a limiting sliding column adapted to one corresponding guiding sliding groove is arranged on each crimping lug boss; each wire-clamping plate is arranged just opposite to one corresponding crimping lug boss; the current transformer comprises an annular induction body; each wire-clamping hole is formed in the corresponding hole cavity of the annular induction body; the bolt is rotated to push each wire-clamping plate to move radially along the tube-pressing part; and a mounting screw hole which penetrates through the wall part of the tube-pressing part in a radial direction is formed in the base tube; and a temperature sensing apparatus is fixedly arranged in the mounting screw hole. The high-voltage electric power zero-sequence current transformer has a real-time temperature monitoring function.