The invention relates to the field of
olefin polymerization catalysts and discloses a preparation method of an
olefin polymerization catalyst. The preparation method comprises the following steps that (1) a
magnesium compound, an
organic phosphorus compound and an organic
epoxy compound are in mutual contact in a
solvent to form a homogeneous solution; (2) at the presence of a
precipitation promoting agent, the homogeneous solution makes contact with a
titanium compound and a mixture is obtained; (3) the mixture makes contact with ester and
alcohol and a
solid-liquid mixture is obtained; and (4) optionally, the
solid-liquid mixture makes contact with an internal
electron donor compound and the
olefin polymerization catalyst is obtained. The invention further provides the olefin
polymerization catalyst prepared by means of the preparation method and an application thereof in an olefin
polymerization reaction. By introducing the ester and the
alcohol in the preparation process of the olefin
polymerization catalyst, the spherical olefin polymerization catalyst with the particle
diameter being 25 microns or above can be prepared, so that preferable mobility is guaranteed. In addition, when the olefin polymerization catalyst is used for the olefin polymerization reaction, the condition that
polymer bulk density is reduced does not occur.