Gas-insulated switchgear（GIS） is one of the most important equipment in power system. Mechanical fault is one of its main fault types. Therefore

GIS mechanical fault diagnosis has very important significance for improving the safety and reliability of power system. The traditional vibration signal analysis method detects mechanical faults by measuring vibrations of single point on the shell which is difficult to fully reflect the mechanical condition of the device. This paper builds an acoustic imaging system suitable for GIS sound field measurement. It uses a directional sound intensity probe to compose the sound field distribution. The performance of the system is verified by the test

and a good foundation is provided for GIS mechanical fault detection technology based on acoustic imaging. It is of great significance to improve the safe and stable operation of GIS.