The invention relates to a method for preparing a special silica-gel carrier of an ethylene polymeriz ation catalyst in a slurry process, which is characterized by comprising the following steps: (a) sufficiently reacting sodium silicate with weight concentration of 10-20 percent and an inorganic acid solution with the weight concentration of 15-25 percent for 1-5 hours according to a weight ratio of the sodium silicate to the inorganic acid solution of 4-6:1, adding an organic solvent at the same time and regulating PH to be 3-4 by using inorganic acid; (b) washing reaction materials in one or more modes of water washing and alcohol washing until the content of sodium ions is below 0.05 percent and then spraying and drying a filter cake at 400-600 DEG C; and (c) controlling the medium grain size of a dried product to be 75-150 micrometers and water content to be below 10 percent to obtain the special silica-gel carrier. The special silica-gel carrier has the technical indexes of 99.5-99.9 percent of silicon dioxide dry basis by weight, 450-600m<2>/g of the specific surface area of BET, 2.0-2.8ml/g of pore volume and 75-150 micrometers of the medium grain size.