The invention relates to a preparation method for pseudo-boehmite from sodium aluminate solution with high causticization factor, which comprises: at 0-3Deg, stirring and leading mixed gas of CO2 and N2 with 30-60Lh-1 per litre solution speed into sodium aluminate solution contained 50.00-250.00gL-1 Al2O3 till the causticization factor down from more than 1.6 to 1.3-1.6; at 0-30Deg, adding 10.0-30.0wt% H2O2 solution with mole ratio as H2O2:Al2O3=3.0~7.0 and feeding time not less than 25min; separating the precipitate from the solution, ageing, filtering, clearing, and drying to obtain the final product. This invention can improve the Al2O3 utilization to reduce cost greatly. |