MgO/η-Al2O3 solid base catalysts with η-Al2O3 as carrier were prepared and used for catalytic hydrolysis of urea in wastewater. X-ray diffraction and N2-BET techniques were applied to characterize the crystal structure and surface properties of catalysts, and back titration method was used to determine the basic sites amount. The effects of MgO loading amount (mass fraction), catalyst dosage, temperature of oil bath and reaction time on urea hydrolysis were respectively investigated. The results show that MgO/η-Al2O3 exhibits excellent catalytic activity for urea hydrolysis, and the urea removal rate increases with MgO loading amount and reaches the maximum when the loading amount is 14.29%. Under the condition of catalyst dosage of 40 g/L, temperature of 170 ℃ and reaction time of 8 h, a low urea concentration of 9.04 mg/L which has met the emission requirement (10 mg/L) is obtained by using 14.29% MgO/η-Al2O3 as catalyst. Furthermore, according to the results of stability tests, MgO/η-Al2O3 demonstrates a good recycling ability.