The present invention relates to a catalyst for preparing syndiotactic polystyrene (sPS), including metallocene titanium compound R1Ti(OR2R3)3 and alkyl aluminoxane, in which R1 is cyclopentadiene group or cyclopentadiene containing 1-5 C1-4 alkyl radicals, R2 is aryl group containing 6-12 carbon atoms and R3 is halogen. When the catalyst system is used for styrene syndiotactic polymerization, it has higher catalytic activity and catalytic efficiency, and its highest catalytic activity is up to 510 kg of polymer/g of titanium hr. and it can be used in industrial production. |