The invention discloses a performance test device for the emitter of the field emission electric thruster of a satellite. The performance test device comprises a vacuum device; a metal positive electrode and a metal negative electrode are arranged in the vacuum device; the negative electrode is electrically connected with the negative electrode of a high-voltage direct-current source; the bottom of the positive electrode is arranged on a heating device and is electrically connected with the positive electrode of the direct-current source; the heating device heats the metal negative electrode; and the negative electrode is provided with a platinum resistor electrically connected with a temperature measuring device outside the vacuum device. When testing is performed, a voltage stabilized direct-current source is adjusted according to temperature displayed by the temperature measuring device, so that the emitter can be heated to required temperature, and a working medium in the emitter can be fully melted; voltage between the metal positive electrode and the metal negative electrode can be stably increased through the high-voltage direct-current source; current in a loop is measured through an ammeter; and therefore, test results such as emission current and turn-on voltage can be obtained.