The invention discloses medicine for treating edema disease of pigs and preparing method thereof. The medicine is prepared from fructus forsythiae, rattlesnake plantain, herba pouzolziae zeylanicae, loofah sponge, phlomis tuberose, winged euonymus twig, hibiscus syriacus, schisandra propinqua, mimosa, osbeckia chinensis, herba aristolochiae, dayflower, stephania japonica, herba penthorum Chinense pursh, kyllinga monocephala rottb, potentilla davica, clerodendrum yunnanense, lysimachia microcarpa, gerbera piloselloides cass, fuzhou diospyros roots, Indian strawberry roots, longhairy antenoron herbs, tropic ageratum herbs, folium rhododendri daurici, mallotus apelta, urena procumbens roots, ficus lyrata, fiveleaf akebia fruit and rhodiola kirilowii rhizome. According to the technical scheme, the medicine has the advantages of being remarkable in effect of treating edema disease with the principle of promoting the circulation of qi, promoting urination, carrying out sterilization and disinfection and removing toxicity for detumescence, capable of enhancing resistance of the pigs, short in treatment course, good in treatment effect, free of medicine resistance and medicine residue, safe, convenient, easy to manufacture, low in cost and capable of effectively controlling the disease state and being popularized in the market.