NOVELTY - Preparing sinomenine hydrochloride capsule, comprises e.g. extracting sinomenine coarse powder, wetting by hydrochloric acid, filling percolator, percolating, stopping percolating, diluting upper column, checking effluent with sediment, diluting using pure water, immersing resin in ammonia solution, diluting by ethanol solution, receiving the eluent and merging, desalting, concentrating, drying, refining, heating reflux, adding active carbon, insulating reflux, filtering, concentrating filtrate, cooling, crystallizing and washing filter cake, and preparing capsule.    USE - The method is useful for preparing sinomenine hydrochloride capsule.    ADVANTAGE - The method is capable of simply and safely preparing the sinomenine hydrochloride capsule in an environmental friendly manner with high yield and purity.    DETAILED DESCRIPTION - Preparing sinomenine hydrochloride capsule, comprises extracting 100-1000 parts by weight (pbw) of sinomenine coarse powder, wetting using 60-1000 volume part of 0.1-1 mole/l hydrochloric acid (HCl) for 0.5-8 hours, filling percolator, adding 0.1-1 mole/l of HCl, percolating at the speed of 2-5 ml/minutes, stopping percolating after 6-24 hours and obtaining percolate, diluting upper column, where the processed cation exchange resin or type 152 resin is filled in the percolator for elution, the diameter-height ratio is 1:8-12 and the sampling speed is 2-5 times column volume/hour, checking effluent with sediment using silicotungstic acid test solution, where no biological alkali spots exist by thin layer chromatography detection, stopping sampling, diluting using purified water until the eluent has no color, immersing resin using 8-15% of ammonia solution or immersing type 152 resin using 3-10% of HCl for 12 hours, diluting using aqua ammonia ethanol solution with a pH of 8-11 or diluting type 152 resin using 3-10% of HCl, where the diluting speed is 2-5 BV/h and the eluent is checked by silicotungstic acid test solution, receiving the eluent when sediment exists, where the received eluent is checked by silicotungstic acid test solution, stopping eluent when no sediment exists, merging eluent, neutralizing pH to 6-8 using HCl or ammonia water, desalting, concentrating and drying to obtain sinomenine hydrochloride coarse product, refining by taking 5-10 pbw of sinomenine hydrochloride coarse product, heating reflux using 30-120 volume part of 10-95% ethanol or purified water until completely dissolving, adding 3-6 wt.% of active carbon, insulating reflux for 10-30 minutes, filtering while hot, concentrating filtrate, cooling, crystallizing, filtering, washing filter cake using 75-95% of ethanol until the filtrate is colorless to obtain sinomenine hydrochloride, preparing capsule by taking 5-45 pbw of sinomenine hydrochloride, 25-65 pbw of deer sugar, 25-45 pbw of starch, 15-45 pbw of microcrystalline cellulose, 0.5-1.5 pbw of magnesium stearate and 30-40 volume parts of 5% povidone aqueous solution, preparing into particles using 5% of povidone aqueous solution, drying and filling the capsule.