The invention provides a metal enclosed bus equipment AC voltage withstanding discharge fault positioning system which is mainly composed of a host and multiple signal acquisition terminals. The signal acquisition terminals adopt an adsorption structure and are placed in areas requiring monitoring to acquire sound decibel values, display sound numerical values, process the numerical values and transmit the numerical values to the host. The host comprises a data processing center with a host signal wireless transmission device. The host receives the data signals of the signal acquisition terminals and performs remote control and graphical analysis and processing. Each signal acquisition terminal is composed of a sound pickup device which is installed in a box shell and acquires sound analog signals, an amplifier and a filter which are connected with the sound pickup device and amplify the analog signals acquired by the sound pickup device, and a first high-speed processor which is connected with signal processing through the connected A/D converter and composed of a secondary control MCU and a peripheral circuit. The metal enclosed bus equipment AC voltage withstanding discharge fault positioning system has the characteristics of being simple in structure and convenient to use so that rapid and accurate positioning of a discharge fault can be realized.