Olefin polymerization catalyst carrier, solid catalyst component and use thereof

A method preparing an olefin polymerization catalyst carrier having a general formula of Mg(ORI)n(ORII)2-n, wherein 0≤n≤2, and RI and RII are same or different, and are each independently selected from a C1-C20 hydrocarbon group;

• and wherein 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, the method comprising the steps of:
• (a) reacting a C1-C20 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;
• (b) optionally drying the first product;
• and
• (c) subjecting the first product obtained in (a) or the dried first product obtained in (b) 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, to thereby obtain the olefin polymerization catalyst carrier.