The invention belongs to the technical field of petroleum catalytic cracking vanadium trapping agent preparation and relates to a method for preparing a catalytic cracking vanadium trapping agent. Thecatalytic cracking vanadium trapping agent is prepared by modifying attapulgite with a surfactant component and by mixing the modified attapulgite with magnesium oxide and an adhesive. The attapulgite is a water-containing magnesium-enriched aluminosilicate clay mineral of a laminated structure, hydrogen bonds can be easily formed among single layers, the hydrogen bonds can be broken by the surfactant component, the surfactant component can be intercalated into the laminated structure and can be easily removed after high-temperature roasting, then a great number of spatial pores can be left,and the specific surface area of the attapulgite can be increased. In the reaction process, vanadium ions can well contact the vanadium trapping agent to form a magnesium vanadium oxide, and furthermore vanadium is immobilized. The vanadium trapping agent made by using the method has a large specific surface area which is up to 200 m<2>/g or greater generally, and has abrasion being smaller than 1.0, and good vanadium trapping capabilities and abrasion resistance.