Provided is an olefin polymerization catalyst carrier with a general structure formula of Mg(OR.sup.I).sub.n(OR.sup.II).sub.2-n, wherein: 0≦n≦2, and R.sup.I and R.sup.II can be the same or different and are each independently selected from a C.sub.1-C.sub.20 hydrocarbon group. In the X-ray diffraction pattern of the catalyst carrier, there are a set of diffraction peaks in the range of a 2θ diffraction angle of 5°-15°, and the set of diffraction peaks contain 1-4 main diffraction peaks. Also disclosed is an olefin polymerization solid catalyst component which is prepared from the carrier Mg(OR.sup.I).sub.n(OR.sup.II).sub.2-n, a titanium compound, and at least one electron donor compound. In addition, also disclosed is an olefin polymerization catalyst containing the solid catalyst component, at least one organic aluminum compound, and optionally, an external electron donor compound.

A method of making an olefin polymerization catalyst carrier with a general structure formula of Mg(OR.sup.I).sub.n(OR.sup.II).sub.2-n, wherein: 0≤n≤2, and R.sup.I and R.sup.II can be the same or different and are each independently selected from a C.sub.1-C.sub.20 hydrocarbon group by reacting an alcohol with a metal magnesium powder under the protection of nitrogen in the presence of a halogen or a halogen-containing compound to obtain a first product, and subjecting the product to a treatment pressure of from 0.2 to 5.0 MPa at a treatment temperature of from 80 to 200° C. for a duration of between 2 minutes and 6 hours. Also provided is a method of making an olefin polymerization solid catalyst component which includes the catalyst carrier, a titanium compound, and at least one electron donor compound.

A method of making an olefin polymerization catalyst carrier with a general structure formula of Mg(OR.sup.I).sub.n(OR.sup.II).sub.2-n, wherein: 0n2, and R.sup.I and R.sup.II can be the same or different and are each independently selected from a C.sub.1-C.sub.20 hydrocarbon group by reacting an alcohol with a metal magnesium powder under the protection of nitrogen in the presence of a halogen or a halogen-containing compound to obtain a first product, and subjecting the product to a treatment pressure of from 0.2 to 5.0 MPa at a treatment temperature of from 80 to 200 C. for a duration of between 2 minutes and 6 hours. Also provided is a method of making an olefin polymerization solid catalyst component which includes the catalyst carrier, a titanium compound, and at least one electron donor compound.