the shallow groundwater is one of the important water resources in renqiu，to study the water chemical characteristics and formation mechanism，this paper on the basis of field investigation and sampling analysis laboratory，on the hydrogeochemical theory as the instruction，with the aid of multivariate statistics method，from various angles to reveal the evolution process of the formation of shallow groundwater in the study area: (1) Through discrete analysis，it is considered that the variation coefficient of major ions in the study area is large，indicating that the shallow groundwater in the study area is obviously affected by human and the hydrochemical characteristics are complex.(2) Through correlation analysis，it is believed that Na+，Ca2+，Mg2+，Cl-，and SO2-4 are the main ions in the original shallow groundwater in the study area，while HCO-3 and NO3-are foreign ions and heterologous ions.(3)According to the cluster analysis，the shallow groundwater in the study area can be divided into three categories: A，B，and C，among which A is in the weathering end of rocks in Gibbs diagram，with low salinity，briny water or fresh water，containing HCO-3 and NO-3，and is affected by agricultural irrigation water.Type B is in the transition from the weathering end to the evaporation and concentration end in Gibbs diagram.Its salinity is in the middle，and it is briny water with relatively high NO-3 content，which is affected by domestic sewage.Class C groundwater is at the end of evaporation and concentration in Gibbs diagram，with high salinity，mainly salt water，poor connectivity with surface water，and close to the original shallow groundwater chemical type. (4) According to the principal component analysis，the original groundwater chemical types in the study area are SO2-4·Cl-—Na+ type and SO2-4·Cl-—Na+·Ca2+type，which are affected by both evaporation in arid environment and seawater intrusion.