The invention discloses a catalyst component for vinyl polymerization. The catalyst component is prepared through a reaction of a magnesium compound containing halogen, a titanium compound and an aminated compound, wherein the aminated compound is at least one selected from a group consisting of alkylamine, arylamine and substituted amine. The invention also provides a preparation method for the catalyst component, a vinyl polymerization catalyst based on the catalyst component and application of the catalyst to vinyl polymerization. The catalyst has good particle morphology; when applied to vinyl homo-polymerization or vinyl co-polymerization, the catalyst has high catalytic activity and good hydrogen response; and a prepared polymer has a large particle surface area and more concentrated particle size distribution and is especially applicable to production of special materials for chlorinated polyethylene and polyethylene cross-linked materials.