Water resource is a high degree of unity between quantity and quality, once the water body suffers from pollution will make the water resources more scarce, and karst groundwater resource is one of the main water resources in the seismic area. In this paper, we chose Baiquanquan area in the low-mountain hilly area at the eastern foot of the south section of Taihang Mountains in H province as the research object, set 25 sampling points and collected 20 groups of karst groundwater samples and 5 groups of surface water samples, and carried out the reliability test by the ion balance method to control the error within ±5%. Based on the karst groundwater samples, the general characteristics of its hydrochemistry were analysed, and its hydrochemical characteristics were explored by cluster analysis. The causes of hydrochemical ions in karst groundwater were investigated by Gibbs plot, chlor-alkali index and saturation index, and the related factors affecting the hydrochemical characteristics of karst groundwater were investigated by factor analysis. The hydrochemical cations and anions in karst groundwater were mainly composed of Ca2+ and HCO3–, and the average concentrations of the two were 132.15 mg/L and 193.66 mg/L, respectively. The cast points of karst groundwater all fell between the dolomite and calcite areas, and their Mg2+/Ca2+ values ranged from 0.11 to 0.75, and the contribution of the F1 factor composed of Ca2+, Mg2+, SO42-, TDS, HCO3– was the maximum of 38.91%. Karst groundwater in the seismic area will be affected by rock weathering, human activities, etc., which will affect the flow path of karst groundwater, and then have an impact on the hydrochemical composition of karst water.