The invention discloses a geothermal water supply system. The geothermal water supply system mainly consists of a geothermal water well, a pump, a water treater, a hot water variable-frequency pump, a coil heat exchanger, an expansion tank, a negative-pressure eliminator, a control cabinet and a hot water pipe network, wherein the pump is mounted in the geothermal water well; outlet water of the pump is connected with a water transmission pipe; the water transmission pipe is connected with inlet water of the water treater; outlet water of the water treater is provided with a connecting pipe for connecting with inlet water of the coil heat exchanger; the connecting pipe enters from the bottom of the coil heat exchanger, and extends to the upper part of the coil heat exchanger; the negative-pressure eliminator is mounted at the top of the coil heat exchanger; and a temperature control transducer is additionally arranged on the coil heat exchanger. The geothermal water supply system has such advantages as energy conservation, economy, safety and good use effect, has the beneficial effects of complete system configurations, high intelligent control degree, complete protective functions, convenience for management and maintenance, low operation cost, and has excellent practical value and promotion prospect in such hot water fields as houses, offices, hotels and bath centers.