[Objective] The water quality of the main stream and main tributary monitoring sections of the North River in 2020 was analyzed in order to provide a reference and basis for monitoring and protecting the water environment of the North River. [Methods] The single factor evaluation method and principal component analysis were used to determine the spatial and temporal trends and driving factors of water quality for the North River. [Results] In 2020, the overall water quality of the North River monitoring sections was good. Only the sections of Shuichetou, Manshui River estuary, Huanglongshui Bridge, and Longgui met the standards for water quality grades Ⅲ—Ⅳ, and the other sections were determined to be grade Ⅱ. Water temperature and dissolved oxygen in the North River were influenced by the seasons. The water body basically remained weakly alkaline throughout the year, and the pollution levels of nutrients and organic matter were higher downstream than at upstream and midstream locations. [Conclusion] Spatial analysis showed that downstream water quality was worse than upstream and midstream water quality. The main influencing factors were nutrients and dissolved oxygen. pH value alone did not have a significant impact on water quality. The seasonal pollution degree followed the order of summer ＞ autumn ＞ spring ＞ winter. The dominant factor on water quality for the entire river was dissolved oxygen, while the dominant factors for the downstream river section were nutrients and organic matter.