So far it is not systemically studied in geological contact relationship between Jinta Basin and Dingxin Valley. Hydraulic connection between Jinta Basin and Dingxin Valley is now hard to conclude. Based on regional data analysis, geological survey is conducted in the study area, and geoelectrical research is also performed. It is compared to find if geoelectrical properties accord with geological contact relationship, and geological contact relationship and hydraulic connection between Jinta Basin and Dingxin Valley are analyzed. Geoelectrical research results show that there is evident one-to-one match between geological contact relationship and geoelectrical properties. The conclusion can be drawn that there are basal bulge consisted of Tertiary glutenite, sandstone and argillaceous siltstone under Heihe River trunk stream, and the basal bulge is accompanied by some faults. Basal bulge and faults form geological contact relationship and hinder hydraulic connection between Jinta Basin and Dingxin Valley. It can provide scientific foundation for underground water resources evaluation, regional ecological condition treatment and recovery of lower Heihe River.