The invention relates to a catalyst component and a catalyst system for olefin polymerization and an application thereof. The catalyst component provided by the invention consists of titanium, magnesium, halogen, and internal electron donor, wherein the internal electron donor comprises 2,2'-dialkyl-1,3-dicarbonate ester compound shown as formula (I). The catalyst component and the catalyst system comprising same provided by the invention are applicable to the development of polyolefin, particularly polypropylene, resin. (img file='DDA0000982154460000011.TIF' wi='348' he='407' /).