Abstract: Transient wave-recording fault indicator is used in transmission and distribution high-voltage 10 kV lines, which consists of collecting unit, A-phase collecting unit, B-phase collecting unit and C-phase collecting unit. The three-phase collecting unit collects the voltage and current data of ABC line respectively, and the collected data is transmitted to the collecting unit through 433 MHz wireless communication. The collecting unit stores and judges the three-phase data, and transmits the results to the master station, thus realizing the monitoring of 10 kV lines and accurate fault location. How to deal with the problems of 433 MHz wireless communication distance change, temperature change, communication interference, etc, which affect the communication quality, has been difficult to solve. Here, some methods are put forward to solve this problem, such as adjusting the receiving gain gear, time slot and transmitting power.