The invention provides a catalyst component for olefin polymerization. The catalyst component comprises Mg, Ti, halogen and an electron donor, wherein the electron donor is selected from at least one unsaturated ring substituted di-acid ester compound as shown in a general formula (I). The invention also provides a catalyst containing the catalyst component and an application of the catalyst in olefin polymerization, and particularly in propylene polymerization. The specific ring substituted di-acid ester compounds in the catalyst component have a positive effect on formation of the catalyst activity center and improvement of the stereoselectivity of the catalyst.