Abstract: In order to study direct detection technology of antistatic properties for non-metallic materials used in coal mine, an electrostatic spark test system was designed, and the change law was analyzed emphatically about the electrostatic voltage required by electrostatic spark igniting methane gas (i.e. methane-air mixture) under typical environmental factors (temperature, humidity, gas concentration, spherical gap). The result showed that the electrostatic voltage required by methane gas ignition decreased continually as the temperature rising and increased with the increase of humidity. It was obtained that the sensitive gap of gas ignition was 1.5 to 2 mm and the sensitive methane concentration was 9.5% to 10% through this test system, which verified the reliability of this test system.