The present invention relates to a preparing method of a health functional drink which is conveniently drinkable, by using vegetable worms, a sulfur duck, and various medicinal herbs. More specifically, according to the drink prepared by the method of the present invention, the sulfur duck is mixed with several medicinal herbs, thereby removing the inherent smell of the sulfur duck and retaining enhanced effects in taste and medical properties, such as anticancer efficacy and immunity, so that the sulfur duck can be used as medical food. Further, the health functional drink prepared by the method of the present invention is not changed despite the storage for a long time, has no repulsive taste, and is conveniently drinkable and easily storable. The method of the present invention comprises: a washing step of removing sebaceous glands from a 2-year old duck fed with a feed added with sulfur and washing the duck； a duck extract extracting step of, based on 500 parts by weight of purified water, mixing 1 parts by weight of vegetable worms and 100 parts by weight of the sulfur duck and heating the mixture in a quartz porphyry pot at 100°；C for 24 hours； a medicinal herb extract extracting step of, based on 500 parts by weight of purified water, mixing 100 parts by weight of garlic, 30 parts by weight of ginger, 20 parts by weight of pine needles, 20 parts by weight of Acanthopanax senticosus, 15 parts by weight of Rehmannia glutinosa, 15 parts by weight of Astragali radix, 15 parts by weight of Angelica, 10 parts by weight of white atractylis, and 10 parts by weight of jujube, and heating the mixture in a quartz porphyry pot at 100°；C for 2 hours and then at 80°；C for 24 hours； and a mixture liquid extracting step of mixing the extract from the duck extract extracting step and the extract from the medicinal herb extract extracting step at a ratio of 1:1 and heating the mixture in a quartz porphyry pot at 100°；C for 10 hours.본 발명의 동충하초, 유황오리 및 각종 한약재를 이용하여 간
