The utility model discloses a one-time wiring apparatus for testing a reference voltage and a leakage current of a 1000-kV lightning arrester. The one-time wiring apparatus is composed of an industrial personal computer, a communication module, a direct-current high voltage generator, a positive-negative adjustable direct-current power supply, an ampere meter A1, an ampere meter A2 and a relay adapter panel. The industrial personal computer is connected with the direct-current high voltage generator and the positive-negative adjustable direct-current power supply by the communication module to carry out data communication; the direct-current high voltage generator and the positive-negative adjustable direct-current power supply are respectively connected in series with the ampere meters and then are connected with the relay on the relay adapter panel; and the relay adapter panel is connected with a tested lightning arrester by a testing line. According to the scheme, the wiring can be carried out conveniently; all test items of the lightning arrester unit can be completed by one-time wiring and thus the repeated wiring replacement can be avoided; the time for power failure can be shortened; and the time and effort can be saved. Therefore, the apparatus has the good application prospects.