An enhancement-mode geothermal system exploitation test apparatus comprises a carbon dioxide steel cylinder, a supercritical carbon dioxide conveying apparatus, a simulated dry and hot rock reactor, a carbon dioxide turbomachine, a high-voltage frequency-conversion plunger pump and a PLC data acquisition system. The carbon dioxide of the carbon dioxide steel cylinder passes through a carbon dioxide flow control valve and a pressure regulating valve, enters into the supercritical carbon dioxide conveying apparatus so that the carbon dioxide is under high pressure, then enters into the simulated dry and hot rock reactor so that a temperature is increased. The high-temperature and high-pressure carbon dioxide after a temperature rise flows into the carbon dioxide turbomachine. The carbon dioxide turbomachine drives a generator or a power machine to carry out energy conversion. The carbon dioxide with a lower grade from the carbon dioxide turbomachine enters into a heat exchanger. The carbon dioxide after heat exchange is sent to the simulated dry and hot rock reactor by the high-voltage frequency-conversion plunger pump so that cyclic utilization is performed.