The invention discloses a qianxi capsule and a preparation method thereof. The capsule is composed of Andrographis paniculata Nees and senecio according to a certain proportion. The preparation method comprises taking a part of the Andrographis paniculata Nees, crushing into fine powder, and sieving; crushing the residual Andrographis paniculata Nees and the senecio into crude powder, percolating, processing the percolating liquid, collecting deposition, and spray drying; adding the above Andrographis paniculata Nees fine powder, starch and proper amount of gelatin, uniformly mixing, preparing into particles, drying and filling to obtain the finish product. The qianxi capsule is safe and effective, has efficacies of clearing away heat and detoxifying, diminishing inflammation and relieving pain and stopping diarrhea shown by pharmacological and clinical studies, and can be clinically used for treating enteritis, colitis, bacterial dysentery, nasosinusitis, etc.