Abstract: Power quality is the cornerstone of the safe and economical operation of power systems and reliable electricity use for users. Based on the engineering practice perspective of traditional electrical engineering technology , this paper systematically analyzes the core issues, monitoring systems, and governance strategies in the field of power quality. It first explains the engineering impacts of core power quality issues such as voltage deviation, frequency deviation, harmonics, and three-phase imbalance, then analyzes the modern online monitoring systems based on a hierarchical distributed architecture and its key technologies. It focuses on discussing the principles and application effects of traditional governance strategies centered on reactive power compensation, filtering technology, and distribution system optimization, and introducing customized power technologies that can comprehensively solve multiple power quality problems in distribution networks. Finally, combination with the development background of new power systems, the paper looks forward to the challenges and development trends of electrical engineering technology in this field, aiming to provide a systematic technical reference for power system planning, operation and maintenance, and power quality improvement.