An ambroxol hydrochloride composition and a preparation method therefor. 0.1%-99.9% by mass of ambroxol hydrochloride and 99.9%-0.1% by mass of scopolamine serving as main ingredients and mannitol are added into water for injection; dissolve, then adjust to pH 5.0; add 0.1% of activated carbon with stirring; filter out the activated carbon, and then filter the liquid; send into a lyophilizer, cool to −40° C., and hold the temperature for 2 hours; warm to −5° C. to 0° C. slowly to lyophilize the liquid, heat to 35° C., and hold the temperature for 3 hours; take out of the lyophilizer to obtain a lyophilized powder injection containing ambroxol hydrochloride and scopolamine; crush the lyophilized powder injection under sterile conditions, and sieve to obtain sterile lyophilized powder containing ambroxol hydrochloride and scopolamine; and prepare various dosage forms by using the lyophilized powder as a raw material.