An olefin polymerization catalyst and preparation method and use thereof are provided. The components of the catalyst comprise an active magnesium halide, a titanium compound containing at least one Ti-halide bond loaded on the active magnesium halide, and an internal electron donor selected from one or more silicon esters compounds having formula (I). The method for preparing the catalyst components is that: adding spherical magnesium chloride alcoholate particles and the electron donor into the solution of titanium compound in sequence, and processing with the titanium compound for one or more times to obtain the catalyst. The catalyst system used for the olefin polymerization comprises the catalyst components, a cocatalyst and an external electron donor. The catalyst has high activity for the propylene polymerization, and the activity is 4399 gPP/gTi·h(50° C., 1 h, slurry polymerization at atmospheric pressure), and the isotacticity of the polymer is 98%.