Abstract: To achieve rapid selection, detection, and localization of single-phase earth faults in distribution networks and to facilitate swift fault resolution by emergency repair teams, a sensor-type fault indicator and system is applied.This paper details the principles behind the detection of single-phase ground faults by this sensor and system, proposing and employing a comprehensive method that integrates the sensor with the existing distribution automation terminals′ zero-sequence current for fault location.Practical applications show this sensor′s high sensitivity to single-phase ground faults, with particular proficiency in detecting metallic single-phase earth faults.The combined use of this sensor and current distribution automation terminals allows for the accurate location of metallic single-phase earth faults.The evaluation of this sensor′s application provides insights that contribute to the advancement of single-phase earth fault handling techniques in distribution networks.