Abstract: Voltage sags in distribution automation systems seriously impact power quality and user equipment safety. By constructing a hierarchical, collaborative sag monitoring architecture, a comprehensive mitigation strategy is proposed that integrates voltage waveform feature extraction, sag source identification, and dynamic voltage recovery. An optimized configuration algorithm is used to determine monitoring point locations, and a DVR device is employed to achieve rapid voltage compensation. Field data demonstrates that this technical solution can increase sag monitoring coverage to over 95% and reduce voltage drops on sensitive loads by 70%, providing technical support for the intelligent operation of distribution networks.