GIS is the key equipment in power transmission and transformation system, and its operation fault seriously affects the reliability of power supply. According to statistics, GIS faults caused by poor contact defects account for 29%. Therefore, this paper builds a GIS test platform to study the characteristics of GIS contact defects. This test platform takes GIS branch bus with disconnector as the main research object and simulates poor contact state by adjusting contact insertion depth. A stable AC current is provided for the test platform through a high current lifter. Relevant data are obtained by temperature sensor, infrared camera and vibration sensor. The equipment in good contact state and poor contact state were compared in terms of temperature and vibration. It is found that when GIS contact is not good, the shell temperature rises and the high-frequency component of vibration signal on the shell increases significantly. It is proved that temperature method and vibration method are feasible to study the GIS contact defects on the test platform.GIS is the key equipment in power transmission and transformation system, and its operation fault seriously affects the reliability of power supply. According to statistics, GIS faults caused by poor contact defects account for 29%. Therefore, this paper builds a GIS test platform to study the characteristics of GIS contact defects. This test platform takes GIS branch bus with disconnector as the main research object and simulates poor contact state by adjusting contact insertion depth. A stable AC current is provided for the test platform through a high current lifter. Relevant data are obtained by temperature sensor, infrared camera and vibration sensor. The equipment in good contact state and poor contact state were compared in terms of temperature and vibration. It is found that when GIS contact is not good, the shell temperature rises and the high-frequency component of vibration signal on the shell increases significantly. It is proved that temperature method and vibration method are feasible to study the GIS contact defects on the test platform.