Abstract: Disclosed is a preparation method of titanium catalyst for olefin polymerization, the method comprising (1) preparing magnesium compound solution by resolving non-deoxidative magnesium halide and IIIA group atom compound in a solvent mixture of cyclic ether, at least one alcohol, phosphorus compound and organosilane with or without hydrocarbon solvent; (2) reacting said magnesium compound solution with titanium compound, silicon compound, tin compound or mixture thereof to produce a support; and (3) reacting said support with titanium compound and electron donor to produce solid complex titanium catalyst, wherein the particle size and particle size distribution f said catalyst are regulated by controlling solubility of the reactants in said steps (2) and/or (3).