As we all know, the rapid development of society is inseparable from the construction of infrastructure, in which the laying of power plays an important role, and the development of the whole society is inseparable from the stable operation of power. If the power failure is not solved quickly, it will have a negative impact on the regional economy, production and life. Therefore, the equipment that can quickly judge the cable fault point is extremely important. Cable fault tester is such a device. The working principle of cable fault tester is to first measure the reflected waveform of low-voltage pulse, and then use high-voltage pulse to impact the fault point passing through the cable to produce arc. When the arc voltage drops to a certain value, the medium voltage pulse is triggered to stably prolong the arc time, and then the low voltage pulse is sent out to obtain the reflected waveform of the fault point. After the two waveforms are superimposed, it can also be found that the divergence point is the corresponding position of the fault point. Because the medium voltage pulse is used to stably prolong the arc time, it is easier to obtain the fault point waveform than the secondary pulse. Compared with the second pulse method, the third pulse method does not need to select the synchronous arc burning time, and the operation is simpler. The triple pulse method adopts the double impact method to prolong the arc time, stabilize the arc, and can easily locate high resistance fault and flicker fault. The triple pulse method has advanced technology, simple operation, clear waveform and rapid and accurate positioning. It has become the mainstream positioning method of high resistance fault and flicker fault. The third pulse method is an upgrade of the second pulse method. Full length and approximate position between cable fault point and test end. The cable fault locator determines the exact location of the cable fault point based on the approximate location of the cable fault point determined by the host of the cable fault tester. For buried cables with unknown direction, the working principle of power cable fault tester: the power cable fault tester is composed of three main components: power cable fault tester host, cable fault locator and cable path tester. The host of cable fault tester is used to measure the nature of cable fault. A Pathfinder is required to determine the underground direction of the cable. The basic method of power cable fault test is to apply high-voltage pulse to the fault cable, the cable fault point is broken down, the cable fault is broken down, the electromagnetic wave occurs when discharging, and sound is emitted at the same time. Let the high resistance fault of the cable click through the arc. At the same time, the low-voltage pulse for measurement is added to the test end. When the measurement pulse reaches the high resistance fault point of the cable, it encounters an arc and the arc surface is reflected. Due to arc combustion, the high resistance fault becomes an instantaneous short-circuit fault, and the low-voltage measurement pulse will have obvious changes in impedance characteristics, so that the waveform of lightning measurement becomes a low-voltage pulse short-circuit waveform, making the waveform particularly simple and clear. This is the so-called secondary pulse method to receive low-voltage pulse fault, which is equivalent to instantaneous short-circuit fault. The low-voltage pulse fault is combined with the traditional high-voltage pulse fault discharge method to discharge the low-voltage pulse fault to a positioning method (the secondary pulse fault is discharged into the high-voltage short-circuit fault in a positioning method, the low-voltage short-circuit fault is discharged, the high-voltage pulse fault is discharged, the low-circuit fault is discharged, the low-circuit fault is discharged, the low-circuit fault is discharged, the low-circuit fault is discharged, the low-circuit fault is discharged, the low-circuit fault is discharged, and the low-circuit fault is discharged.