Abstract: The present disclosure relates to olefin polymerization catalysts, and discloses a catalyst component for olefin polymerization or copolymerization and a preparation method therefor, and a catalyst and an application thereof. The catalyst component for olefin polymerization or copolymerization in the present disclosure comprises titanium element, magnesium element, an electron donor, an organic silicon polymer, and an inorganic oxide support, wherein the molecular composition of the organic silicon polymer is [RxSiO(4-x)/2]m, wherein R is selected from alkyl, aryl, vinyl or oxygen, x is 0 or more and 2 or less, and the value of m makes the number-average molecular weight of the organic silicon polymer be 1×103-1×106 g/mol.

Abstract: The present invention is to provide a composite carrier, which is spheric particles obtainable by contacting magnesium halide with one or more electron donor compounds to form a solution, then mixing the solution with silica material having an average particle size of less than 10 microns to form a mixture, and drying the mixture through spray drying process. The present invention is also to provide a catalyst component comprising said composite carrier. When the catalyst component is used together with a cocatalyst component in propylene polymerization, it exhibits higher polymerization activity and stereospecificity, and can be used to prepare high impact resistent ethylene-propylene copolymer having high ethylene content.

Abstract: The present invention is to provide a composite carrier, which is spheric particles obtainable by contacting magnesium halide with one or more electron donor compounds to form a solution, then mixing the solution with silica material having an average particle size of less than 10 microns to form a mixture, and drying the mixture through spray drying process. The present invention is also to provide a catalyst component comprising said composite carrier. When the catalyst component is used together with a cocatalyst component in propylene polymerization, it exhibits higher polymerization activity and stereospecificity, and can be used to prepare high impact resistant ethylene-propylene copolymer having high ethylene content.