Widely developed Cretaceous red sandstone and argillaceous sandstone outcropped in Jurong of Jiangsu, which were shallowly buried in unconsolidated layers under very poor geological conditions. Because of the shortage of groundwater, most drilling encountered dry holes. Only by simple drilling, the initial output of the geothermal well in Jurong was about 2～3m3/h. After the analysis on geological conditions of water-bearing, some new process theories of construction, well washing and pumping were put into application: deep water pump and “sand discharge by pulsation”, and sorting pumping horizon; water output was up to more than 500m3/day. The success in this well has practice value with reference significance to the water research in water-lacking layer and well-flushing in clastic rocks.