NOVELTY - Preparing sinomenine hydrochloride eye drops, comprises (i) preparing yellow sinomenine hydrochloride crude product, and (ii) dissolving sinomenine hydrochloride crude product using ethanol, adding activated carbon, thermal insulating, refluxing, filtering, crystallizing, and filtering to obtain filter cake, washing filter cake to obtain sinomenine hydrochloride, taking water for injection, charging nitrogen, adding sinomenine hydrochloride, dissolving, adding e.g. sodium bisulfite, stirring, charging nitrogen, adding activated carbon, thermal insulating, filtering, sterilizing, and filling.    USE - The method is useful for preparing sinomenine hydrochloride eye drops.    ADVANTAGE - The method has simple operation process; utilizes the extraction process, which does not require heating, soaking and cooling; produces product of high yield; and is safe, reliable, and environmental friendly.    DETAILED DESCRIPTION - Preparing sinomenine hydrochloride eye drops, comprises (i) using caulis sinomenii crude powder (10-100 parts by wt.), 0.1-1 mol/l hydrochloric acid (60-1000 parts by vol.), wetting for 5-8 hours, installing percolation tube, adding hydrochloric acid (0.1-l mol/l) so that liquid level covers 2-6 cm, impregnating for 6-48 hours, and percolating at a speed of 2-6 ml/minute for 6-24 hours, and stopping percolating to obtain percolation fluid, extracting by adding lime milk in percolation fluid to adjust the pH to 10.5-12, filtering, adding hydrochloric acid to adjust the pH to 7-9.5, extracting for 2-5 times by chloroform, mixing the chloroform layer and washing using water until it is neutral, adding anhydrous sodium sulfate (3-6%), vacuum extracting, concentrating and recycling chloroform, and crystallizing by dripping hydrochloric acid (6 mol/l) into the concentrate to adjust the pH to 2-4, stirring until the floating solid disperse, refrigerating, filtering, removing the filtrate, and drying the filter cake at 60-70 degrees C to obtain the yellow sinomenine hydrochloride crude product, and (ii) carrying out refining process by taking sinomenine hydrochloride crude product (5-10 parts by wt.), dissolving completely using 10-95% ethanol (30-120 parts by vol.) or heating and refluxing purified water, then adding activated carbon (4%), thermal insulating, refluxing for 10-30 minutes, filtering when it is hot, concentrating the filtrate, cooling, crystallizing, and filtering to obtain filter cake, using 95% of alcohol to wash filter cake until the filtrate is colorless to obtain sinomenine hydrochloride, taking raw materials (in parts by wt.) sinomenine hydrochloride (10-40), sodium bisulfite (0.5-5), disodium edetate (0.1-0.5), and injection water to prepare 1000 parts by volume, and preparing the eye drop by taking water for injection, charging nitrogen, adding sinomenine hydrochloride and stirring to dissolve, and then adding sodium bisulfite and disodium edetate, stirring to dissolve, charging continuously nitrogen, adding activated carbon (0.05-0.5%), thermal insulating at 35-45 degrees C for 10 minutes, filtering to remove activated carbon, supplementing full amount of injection water, and filtering using 0.25-0.65 mu m and 0.10-0.30 mu m filter, sterilizing, and filling to obtain the final product.