The present invention relates to the medical use of Capers or Capers extracts, specifically provides Capers or Capers extracts in the preparation of medicines for reducing tripterygium wilfordii, tripterygium glycosides or triptolide hepatotoxicity or The application in health products also provides a composition and its preparation for preventing and treating rheumatoid arthritis, glomerulonephritis, nephrotic syndrome, lupus erythematosus, dry eye syndrome, Behcet's disease, eczema, psoriasis , leprosy, scabies, ringworm, Hashimoto's thyroid or tumor medicine or health care products, the composition comprises component i) and component ii), and the component i) is selected from: Capers or the extract of capers; the component ii) is selected from: tripterygium glycosides or triptolide.