Abstract: SO42-/SnO2-Nb2O5 solid superacid catalyst was prepared by azeotropic dechlorination method, using n-butanol and anhydrous alcohol as solvents, a filtration step could be omitted, and thus the catalyst preparation time was much shortened. The prepared catalyst was characterized by XRD, FT-IR, TG-DTA and its catalytic performance was evaluated using isomerization of α-pinene as probe reaction. Test results showed that the optimum preparation conditions of SO42-/SnO2-Nb2O5 solid superacid catalyst were as follows: a Nb2O5/SnO2 mass ratio of 0.25, the concentration of impregnating sulfuric acid solution was 0.50 mol/L and calcined at 500 ℃ for 2.0 h; catalyst prepared under such conditions exhibited good catalytic performance in isomerization of α-pinene, the conversion of α-pinene and selectivity of camphene was 100% and 66.49%, respectively. Compared with other preparation methods, such as precipitation and sol-gel methods, catalyst prepared by azeotropic dechlorination method was better.