Abstract: In order to improve the sensitivity of the intrinsic safe spark test device and to improve the inspection efficiency, based on the structure of the intrinsic sa fe spark test device and the requirements of the rated circuit, with the rational preparation and tungsten wire cleaning, cadmium disc adjustment, device loop parameter s improved, the application of flow method to air distribution and the application of scavenging method to the inlet air distribution were applied to improve the uniformity the prepared mixed gas in order to improve the sensitivity of the intrinsic safe spark test device.The paper had a detail introduction on each method.The practices show ed that the comprehensive application of the above method could well improve the sensitivity of the device and highly upgrade inspection efficiency and test quality of t he intrinsic safe equipment.