Supported non-metallocene catalyst used for ethylene polymerization

The invention relates to a supported non-metallocene catalyst used for ethylene polymerization and a preparation method thereof. The catalyst comprises a non-metallocene compound, chlorinated alkyl silicon, halogenated alkyl magnesium, alkyl aluminoxane and a silica gel carrier reaction product; the preparation method comprises the following steps: 1) preparation of a chlorinated hydroxyl silicon modified silica gel carrier, 2)preparation of a halogenated alkyl magnesium modified silica gel carrier, 3)preparation of an alkyl aluminoxane modified silica gel carrier, and 4)preparation of the silica gel supported non-metallocene catalyst; and the obtained non-metallocene catalyst has high polymerization activity for catalyzing vinyl polymerization or copolymerization. The preparation method of the silica gel carrier is simple, and the obtained supported catalyst particles have good morphology and have adjustable size.