Preparation method of ethylene polymerization catalyst, catalyst prepared by preparation method and application of catalyst

The invention relates to the field of catalysts, in particular to a preparation method of an ethylene polymerization catalyst, the catalyst prepared by the preparation method and application of the catalyst, and the method comprises the following steps: (1) providing a solution containing a magnesium compound and alcohol in a protective atmosphere; (2) adding an electron donor-I, a titanium compound and halogenated hydrocarbon into the solution, and carrying out a first coordination reaction to obtain a catalyst intermediate; and (3) carrying out second coordination reaction on the catalyst intermediate and an electron donor-II. The catalyst prepared by the preparation method provided by the invention is uniform in particle, stable in activity release, slow in activity attenuation and good in copolymerization performance, the high activity of the catalyst is realized, and the catalytic activity attenuation of the catalyst is delayed. 本发明涉及催化剂领域，具体涉及一种乙烯聚合催化剂的制备方法以及由该制备方法制得的催化剂及其应用，该方法包括以下步骤：(1)在保护性气氛下，提供含有镁化合