The invention discloses a cable joint and a connecting method thereof. The cable joint comprises an eccentric pipe and a sealing portion, wherein oil pipes are fixedly connected to two ends of the eccentric pipe respectively, and a U-shaped notch is arranged in a side surface of the eccentric pipe; the sealing portion is fixedly connected into the U-shaped notch, cables penetrate into the two sides of the sealing portion respectively, and cable cores of the cables are hinged in an internal portion of the sealing portion. The sealing portion comprises a sealing short section, a joint, a card sleeve and a pressing head, wherein a cavity is arranged in the sealing short section, and internal threads are processed at two ends of the cavity respectively; a through hole is arranged in the joint, and the joint is connected to two ends of the sealing short section through threads; the card sleeve is conical, one end with a smaller diameter of the card sleeve is clamped into the through hole,and one end with the larger diameter is exposed out of a portion, away from a sealing short section end surface, of the joint; and the pressing head is in threaded connection with the joint. The invention aims at solving problems of easy collision, easy disconnection, poor sealing performance, a complex binding process and the like during connection of cables used in oil field wells at present.