The invention discloses traditional Chinese medicine decoction for treating nephritis and a preparation method thereof. The traditional Chinese medicine decoction is prepared by decocting radix achyranthis bidentatae, gynostemma pentaphylla, dioscorea nipponica makino, perilla leaf, herba polygoni avicularis, ophiopogon japonicus, radix astragali, herba houttuyniae, caulis spatholobi, Chinese ladiestresses root or herb, ginger, wolfberry and rhizoma chuanxiong. The traditional Chinese medicine decoction has the advantages that the decoction uses the treatment rules of promoting blood circulation to dissipate stasis, activating meridians to stop pain and tonifying the liver and kidney, various medicinal materials are combined to achieve a synergic effect, and the decoction is mainly used for promoting blood circulation to dissipate stasis, activating meridians to stop pain, replenishing blood and nourishing yin, enhancing body immunity, reinforcing vital energy, mobilizing five internal organs, nursing six hollow organs, comprehensively nursing health and improving human body function and has evident curative effect on the nephritis; the decoction is simple to prepare, good in absorption effect, lasting in medicine effect, evident in curative effect, free of toxic and side effects, high in safety, low in production cost, and capable of timely relieving the symptoms of patients, eradicating the root causes of the nephritis and radically curing the nephritis.