The invention relates to a preparation method of dianthus chinensis tea, which comprises the following steps: picking the dianthus chinensis and screening and baking; after taking the dianthus chinensis out of the drying room, placing for cooling for 20-24 hours; after the dianthus chinensis becomes soft, sub-packaging to obtain dry tea; decocting the dry tea and combining the filtrate; and concentrating, standing, filtering, concentrating, drying, sterilizing, cooling to room temperature and sub-packaging into teabag paper bags, and sealing to obtain teabags. The preparation method is scientific and reasonable and simple and easy to implement and has high production continuity; the types of the obtained medicinal tea are diverse, and the purity of the dianthus chinensis extract is high; the baking temperature is moderate, the time is proper, and a good aroma extraction effect can be realized; and the medicinal active ingredients of dianthus chinensis tea can be maintained to the greatest degree, and the nutritional value is increased. In the dianthus chinensis tea prepared by the method provided by the invention, the tea soup has emerald green and golden yellow bright color as well as faint and pleasant scent; and the dianthus chinensis tea has the functions of clearing heat and excreting water, breaking blood and dredging channels, relieving swelling and pain, improving eyesight and removing nebula and the like as well as the characteristics of easiness in carrying, convenience in use, nature and pureness and the like.