It is of great significance for the exploitation and utilization of water resources in the basin to study the isotope hydrochemical characteristics and the interactions between the river water and groundwater. Here, the Wulanmulun River Basin in the Yellow River Basin, which is located in Shenfu Dongsheng Coalfield, is taken as the research object and the statistical analysis, Piper diagram and two-end meta-model as the research methods. The chemical characteristics, hydrogen and oxygen stable isotopic characteristics and distribution of the precipitation, river water, groundwater (including mine drainage and domestic well water) in the basin are analysed to explore the supply relationship between the precipitation, river water and groundwater. The hydrochemical analysis shows that the hydrochemical types of river water are HCO3-Na and HCO3+SO4-Na, mine drainage water are HCO3-Na, HCO3+Cl-Na and HCO3+ SO4-Na, domestic well water is HCO3-Ca. Mine drainage water is closely related to river water. Isotopic analysis shows that groundwater is co-replenished by atmospheric precipitation and river water, and there is a hydraulic connection between the three and a certain degree of water transformation can be spotted as well. When the depth of groundwater well is shallower than 135 m, the contribution of river water to its recharge is 58.47%-80.94% , and when the depth of groundwater well is deeper than 135 m, the contribution of river water to its recharge is 21.47%-58.69%. The contribution of river water to groundwater recharge is more than 45% in the range of 8.8 km from the groundwater sampling point to the river course, which indicates that river water is one of the important sources of groundwater recharge. When the groundwater sampling point is more than 8.8 km away from the river, the contribution of the river water to its recharge is weak. The contribution rate of river water to groundwater recharge decreases with the increase of the well depth and distance from the river. This study can provide some technical support for water resources management and protection in the basin.