The invention discloses a coaxial conductor joint which comprises a coaxial socket and a coaxial plug. The coaxial socket comprises a socket compaction nut, a compaction nut cutting sleeve, a cutting sleeve nut, an outer shielding housing, a built-in O-shaped obturating ring, an outlay O-shaped obturating ring, a rigid conductor insulating envelope, a lock pin insulating envelope and a metal lock pin; the coaxial plug comprises a connecting nut, a metal contact pin, a inner insulating contact pin seat, an outer contact pin seat, a connecting sleeve, a compaction bolt, a compaction bolt cutting sleeve and a plug compaction nut. The insulating envelopes adopts high-performance polyether-ether-ketone plastic; coaxial socket sealing is realized by the metal cutting sleeves and the obturating rings, and the electrical connecting from a coaxial cable to a rigid conductor is realized by the lock pin matching with the contact pin. The invention has simple structure, good leak tightness, convenient operation, long service life, good anti-interference and irradiation resistance, is convenient for part maintenance and interchanging, and suitable to be used on an electrical perforating piece of a reactor safe shell, and also can be used on relative equipment of spaceflight and chemical engineering.