The invention provides a method for extracting sinomenine hydrochloride. The method comprises the following steps: S1, percolating caulis sinomenii with hydrochloric acid to obtain a caulis sinomeniipercolation liquid; S2, extracting the caulis sinomenii percolation liquid obtained in S1 with an organic solvent, and drying the organic phase to obtain a crude sinomenine hydrochloride; and S3, dissolving the crude sinomenine hydrochloride obtained in S2 in an alcohol, performing decolorizing, and recrystallizing sinomenine hydrochloride by a gradient cooling method to obtain sinomenine hydrochloride.