Ru-B/γ-Al2O3 catalyst was prepared by reductant impregnation method, which was applied in the selective hydrogenation of ethyl 1H-indole-2-carboxylate for producing ethyl 2,3,3a,7a-tetrahydro-1H-indole-2-carboxylate with hydrogen as reductant. Furthermore, we discussed the influences of substrate concentration, reaction solvent, hydrogenation temperature, initial hydrogen pressure and reaction time on the catalytic performance of the as-prepared catalyst. The obtained Ru-B/γ-Al2O3 catalyst showed a high-efficiency for the selective hydrogenation of ethyl 1H-indole-2-carboxylate(>99% conversion and selectivity) in i-propanol used as solvent at a concentration of 10%(mass fraction) of ethyl 1H-indole-2-carboxylate, a pressure of hydrogen of 6 MPa and a reaction temperature of 373 K.