NOVELTY - The method comprises preparing extracting coarse product of sinomenine hydrochloride injection by wetting 800 parts by weight (pbw) of caulis sinomenii coarse powder with 300 parts by volume of 0.8 mol/l of hydrochloric acid for 1 hours, equipping a percolator and then adding 0.2 mol/l of hydrochloric acid with the mixture to obtain 5 cm of liquid layer on the powder and then soaking for 36 hours, percolating the mixture with a speed of 6ml/minutes and then stopping percolating after 8 hours to obtain a percolate, and adding lime milk to the percolate and then adjusting the pH value to 11.3.    USE - The method is useful for preparing sinomenine hydrochloride injection.    ADVANTAGE - The method is capable of simply, safely and reliably preparing the sinomenine hydrochloride injection with high yield and without pollution.    DETAILED DESCRIPTION - The method comprises preparing extracting coarse product of sinomenine hydrochloride by wetting 800 parts by weight (pbw) of caulis sinomenii coarse powder with 300 parts by volume of 0.8 mol/l of hydrochloric acid for 1 hours, equipping a percolator into the mixture and then adding 0.2 mol/l of hydrochloric acid with the mixture to obtain 5 cm of liquid layer on the powder and then soaking for 36 hours, percolating the mixture with a speed of 6ml/minutes and then stopping percolating after 8 hours to obtain a percolate, adding lime milk to the percolate and then adjusting the pH value to 11.3, filtering the solution and then adding hydrochloric acid to adjust pH value of 7, extracting the solution with chloroform for 5 times, merging the chloroform layers and then washing to neutral with water, adding 6% of anhydrous sodium sulfate into the solution and then dehydrating, reducing pressure and concentrating the solution to recover chloroform, dripping 6 mol/l of hydrochloric acid to the concentrated solution and then adjusting pH of 2, stirring the solution to disperse floating solid, refrigerating and filtering the solution, removing the filtrate, drying the filter cake at 68 degrees C to obtain a yellow coarse product of sinomenine hydrochloride, refining the sinomenine hydrochloride by heating to dissolve 6 pbw of coarse product of sinomenine hydrochloride by adding 40 parts by volume of 80% of ethanol or purified water and then adding 4% of activated carbon, preserving heat and refluxing the solution for 15 minutes, filtering the solution while it is hot, concentrating the filtrate, and cooling, crystallizing, filtering and washing the filter cake with 95% of ethanol until the filter cake is clear to obtain sinomenine hydrochloride. The method further comprises taking sinomenine hydrochloride (25 pbw), sodium hydrogensulfite (1 pbw), disodium edentate (0.3 pbw) and water for injecting, charging the solution with nitrogen and then adding sinomenine hydrochloride, stirring the solution to dissolve and then adding sodium hydrogensulfite and disodium edentate, stirring the solution to dissolve and then keeping on charging with nitrogen, adding 0.1% of activated carbon into the solution and then preserving heat at 35-45 degrees C for 10 minutes, filtering the solution to remove carbon, replenishing the water for injecting to 1000 parts by volume, checking and filtering the solution to clear and then charging with nitrogen and potting, and sterilizing the solution at 100 degrees C for 30 minutes to obtain end product.