The synchronization method based on the sound and magnetic makes power cable precise positioning more intuitive in this paper,which based on the pre-positioning of the cable fault an accurate fault location method.First the pulse generator discharges pulse applied to the cable, the fault point will release the sound signal and an electromagnetic signal. But the electromagnetic signal propagation speeds approaching the speed of light instantaneously reaches the point of failure.when the electromagnetic signal is detected , the microcontroller timer T1 is informed. T1 starts counting until up to the sound signal is detected. the LCD will display the counting result, and along the cable to we will find the minimum point of the time value ,which is the location of the fault point.