Preparation method of propylene polymerization solid titanium catalyst component

The invention relates to a preparation method of a propylene polymerization solid titanium catalyst component, adopting a one-step preparation technology. The preparation method comprises the following steps of forming a mixing and dispersing system by mixing magnesium halide, a alcohol compound, an organic phosphorus compound, silicone oil and an inert diluent with a certain proportion; adding titanium halide or a derivative thereof, and precipitating a solid substance under the action of an aid-precipitation agent; and obtaining a catalyst component by further treating the solid substance with multiple carboxylic esters as well as also the titanium halide and the inert diluent, wherein the average particle size of the obtained catalyst component is 5-100 microns, the specific surface area of particles is larger than 100m /g, the titanium content is 1.5-5wt percent, and the magnesium content is 10-20wt percent. The catalyst component is in an approximately spherical shape, and the polymer isotacticity is high and is adjustable within a certain range, therefore, the polymer catalyst component can be well suitable for propylene polymerization.