This invention relates to a method for producing low-carbon olefins by catalytic cracking. The method comprises: performing catalytic cracking on raw materials containing naphtha, lightweight diesel oil and hydrogenation tail oil in two series catalyst bed layers filled with different catalysts to obtain low-carbon olefins. The method has such advantages as high conversion rate of raw materials, high reaction selectivity, high yield of ethylene and propylene, convenient operation of catalysts, and convenient maintenance of equipments. Preferentially, the method adopts two series fixed-bed reactors with two different catalyst beds, or one fixed-bed reactor with two different series catalyst beds. The method has such advantages as increased conversion rate of raw materials, improved reaction selectivity, increased yields of products (ethylene and propylene), convenient loading/deloading of catalysts, and convenient maintenance of equipment.