The present invention discloses a traditional Chinese medicine composition to treat Rheumatoid Arthritis and its preparation method. The composition is mainly comprised of the following crude drugs: ant, Radix Salviae Miltiorrhizae, Radix Aconiti Preparata, Radix Ginseng, Caulis Spatholobi, and Ramulus Cinnamomi, etc. According to pharmaceutical methods, various clinical acceptable dosage forms can be prepared of the composition of the present invention, including but not limited to one of the following dosage forms: tablets, capsules, pills, granules, suspension, dripping pills, oral liquid preparation, etc. The drug of the present invention has the functions of invigorating the kidney and spleen, promoting blood flow and clearing out the vein, expelling wind-evil and removing wetness, eliminating cold to stop pain. It can be effectively used in the treatment of lingering arthralgia with weak, arthralgia, intumesce and morning stiffness, numbness and stickiness, difficult to flex and extend, rigor and deforming, the rheumatism and rheumatoid arthritis with the above symptoms.