The invention discloses a glass fiber blanket and a producing method thereof. The method comprises the steps of mixing the following components , by mass, 35-40 parts of silica flour, 5-12 parts of feldspar, 9-14 parts of borax, 1-3.5 parts of calcite, 6-8 parts of dolomite, 11-14 parts of soda ash, and 15-25 parts of sheet glass to form a mixture; melting the mixture to obtain glass metal; placing the glass metal in a centrifugal machine for spinning treatment to obtain glass fiber and spraying water and binders onto the surface of the glass fiber in a vaporific mode at the same time; placing the glass fiber coated with the binders in a cotton collecting machine to enable the glass fiber to evenly fall onto the cotton collecting machine under the action of a negative-pressure fan to form a glass cotton layer; and conveying the glass cotton layer well laid to a curing oven through a conveyer to be cured to obtain the glass fiber blanket.