Preparation method for spatholobus suberectus dunn analgesics

The invention discloses a preparation method for spatholobus suberectus dunn analgesics, which comprises the following steps: crushing spatholobus suberectus dunn, decocting the spatholobus suberectus dunn in water twice for 1-2 h every time, concentrating the decoction, and leaving the decoction to stand; filtering the decoction and rejecting sediment; diluting the spatholobus suberectus dunn filtrate with distilled water, and conducting membrane separation; collecting four stages of membrane-separated liquid UF-100, UF-50, UF-10 and UF-5, and conducting vacuum freeze drying to obtain freeze-dried powder; adding conventional adjuvants into the freeze-dried powder UF-100, UF-50, UF-10 and UF-5 and mixed freeze-dried powder respectively to prepare various preparations by conventional techniques, wherein the mixing ratio of UF-100 to UF-50 to UF-10 to UF-5 of the mixed freeze-dried powder is 5:3:1:1. The preparation method for the spatholobus suberectus dunn analgesics, provided by the invention, has the characteristics of safety, environment friendliness, no toxicity and simple process.