The invention discloses double-machine switch extending equipment, comprising transmitting-end equipment and receiving-end equipment, wherein the transmitting-end equipment is connected with two computers respectively; the transmitting-end equipment is provided with a double-machine arbitration unit, an encoding/decoding unit and the like; and the transmitting-end equipment is connected with the receiving-end equipment by an optical fiber. The transmitting ends of externally extending equipment of the computers and double-machine hot-spare arbitration equipment are combined into the transmitting ends of the double-machine switch extending equipment; the receiving-end equipment is extended by the digital encoding/decoding and optical fiber, so that the whole equipment has the functions of the extending equipment and the arbitration equipment, the extension of the double-machine hot-spare arbitration equipment and the external equipment can be realized, and simultaneously, the conditions of installation, use and maintenance are improved.