Main catalyst component for alkene polymerization and catalyst

The invention provides a main catalyst component for alkene polymerization and a catalyst. The main catalyst component is prepared from a magnesium compound, an oxygen-containing titanium compound, a chlorine-containing compound, an acyl chloride compound and a titanium tetrahalide, and has the advantages of good particle morphology, and uniform particle size distribution. The catalyst of the invention is mainly prepared from the main catalyst component, an organic aluminum compound, an organic silane compound, has the characteristics of high catalytic activity, uniform particle morphology, and narrow particle size distribution, and is suitable for olefin polymerization, especially propylene gas phase polymerization and bulk polymerization processes. Because titanium tetrachloride amount in the catalyst preparation is reduced, the preparation cost of the catalyst is significantly reduced. And when the catalyst of the invention is employed, the size distribution of a polymer product is narrowed and the over thick or over thin polymer product decreases due to the copy effect of the particle morphology.