The geothermal resources of the Gaoyang low uplift in the Xiong’an New Area are of high quality. In the past there was limited exploration, development and utilization of the Gaoyang low uplift resources. At present, the heat storage is mainly used in the shallow Guantao sandstone formation. For the planning and construction in Xiong’an New Area, exploration of the deep heat storage of Gaoyang low bulge in search for highquality geothermal resources is urgently needed. Based on the 3500 m deep D35 borehole in the northcentral part of the Gaoyang geothermal field, this paper studies the heat storage characteristics and main parameters of the thermal storage karst heat storage of the Wumishan Formation through pumping and water sample tests. The main conclusions are as follows: (1) the fractured karst thermal reservoir of the Wumishan Formation is mainly dolomite and argillaceous dolomite. The total thickness of fracture (water layer) is 43 m, accounting for 19.68% (fracture rate) of the total thickness of the formation. The average voids are 3.93%, and the average permeability is 3.16×10-3μm2; (2) ten karst fracture zones with a total thickness of 250 m were developed in the borehole D35 at depths of 3600~3850 m. The water temperature of the D35 orifice is 106.6 ℃, the maximum temperature at the bottom of the hole is 116 ℃; (3) the pumping test curve of D35 borehole has the mixed characteristics of water and steam, the pumping flow of the well is 170 m3/h, and the heating potential of the single well is 385000 m2, indicating it to be the largest capacity geothermal well in Xiong’an New Area.