This article offers a summary of pertinent information regarding power quality in distribution systems, aimed at fostering technological advancements in the observation and enhancement of power quality. This article provides an overview of the impact of distributed power sources on distribution networks, leading to a decrease in power quality. Specifically, we have elaborated on the factors that affect power quality. Secondly, a reasonable analysis was conducted on various power quality assessment systems and technical methods dedicated to improving power quality. Finally, we discussed some key challenges and predicted future development trends.