Abstract: The Yellow River basin is an important ecological barrier and economic zone in China. The upper, middle and lower reaches of the Yellow River are faced with different ecological environmental problems. Water plays an important role in the formation and evolution of ecological environmental problems. Based on the quantities, qualities, settlements and dynamic characters of groundwater, the groundwater resources and the drinking water safety of the YRB were analyzed. The results show that total avenue groundwater resource of the YRB in 2019 is 3.93×10¹⁰ m³. Groundwater resources in seven key plain regions, such as Yinchuan plains and Hetao plains, is 8.19×10⁹ m³, contributing more than 20% groundwater resources of the whole basin. The groundwater qualities in YRB dominated is mainly classified as Ⅰ-Ⅳ grade. The concentration of total hardness, sulfate, iron, TDS and Cl-exceed the groundwater standard at high rate. Excessive arsenic, fluoride, selenium, iodine and other primary components threaten the local drinking water safety. Compared with the same period in 2019, the groundwater table kept stable in the upper reach, local rising in the middle reach and decreasing in the lower reach in 2020. The morphological characters of main groundwater depression cone kept basically stable. Focusing on the key regions of the YRB, such as the sources area, Hetao Basin, etc., based on the analysis of the eco-environmental problems, it is proposed to carry out the whole basin resource survey and assessment, deeply develop water balance research in the whole basin and key regions.