The invention discloses a preparation method of arotinolol hydrochloride. According to the preparation method, 2-carbamoyl-5-(2-mercapto-1,3-thiazol-4-yl)-thiophene is used as a starting material and subjected to S-alkylation, ammonolysis and salifying, and arotinolol hydrochloride is obtained. The method is easy to operate, higher in yield and suitable for industrial production, and separation and purification of intermediate products are increased, so that arotinolol hydrochloride can meet pharmaceutical requirements without refining after being salified.