Cordyceps is a fungus that lives on certain caterpillars in the high mountain regions of China. It is sometimes used as a medicine. Most supplements use cordyceps that is made in a lab. Although cordyceps is sometimes called a mushroom, the type of cordyceps that is made in a lab does not grow a mushroom. Cordyceps is a fungus that has long been used in in traditional Chinese medicine (TCM). Some people use it to try to boost energy and strength, improve immunity, enhance kidney function, and improve sexual dysfunction. It has also been used to treat cough and fatigue. According to the extraction method for cordycepin provided by the invention, cordycepin is extracted by applying a hot water extraction method, so that the structure of cordycepin in the alcohol extraction process is prevented from being damaged by a solvent and cordycepin breakage caused by microwaves and ultrasonic .