Preparation method of catalyst for preparing acrylic acid through oxidizing acrolein

The invention relates to a catalyst for selectively preparing acrylic acid through using acrolein, and a preparation method thereof. The problems of many preparation steps, complex process and low activity and selectivity of catalysts in the prior art are mainly solved. A technical scheme adopted in the invention is characterized in that a preformed catalyst is obtained by tabletting a powdery catalyst with at least one of SiO2, Al2O3 and TiO2 as a carrier and molybdenum oxide and vanadium pentoxide as active components. The above technical problems are well solved, and the preparation method can be used in the industrial production of the catalyst for preparing acrylic acid through oxidizing acrolein.