The invention provides a supercritical extraction device of a radix ampelopsis extract and an extraction method thereof, and relates to a radix ampelopsis extract. The device is provided with a carbon dioxide storage tank, a filter, a cooling liquid circulating pump, a high-pressure pump, a pressure regulating valve, an extractor, a heater, a reducing valve, a separation collector, a cooler and a flowmeter. The extraction method comprises the following steps of: crashing and screening out radix ampelopsis root tuber particles; putting the radix ampelopsis root tuber particles into the extractor, and adding an entrainer, adjusting the pressure in the extractor, and heating; controlling the cooler to cool so that the temperature of the separation collector is controlled at a specified temperature; starting the cooling liquid circulating pump, opening a valve and starting the high-pressure pump; causing the extracting agent carbon dioxide to pass through the filter and pressurizing the extracting agent by the high-pressure pump, and then causing the pressurized carbon dioxide to enter the extractor to extract the radix ampelopsis root tuber particles; after set extraction time, and after decompression of the radix ampelopsis extract obtained by the extractor, collecting an extract solution in the separation collector by using a dissolving collecting solvent, weighing the extract solution and then performing decompression distillation and freeze-drying, thereby obtaining the radix ampelopsis extract.