The present disclosure discloses a silica gel vibrating diaphragm and a method for fabricating the same. The method comprises: forming a composite material belt by using two layers of a base material and liquid silica gel in a calendering manner, wherein the liquid silica gel is between the two layers of the base material; wholly hot-press molding the composite material belt by a vibrating diaphragm die holder, a temperature of the hot-press molding being higher than a vulcanization temperature of the liquid silica gel; removing the two layers of the base material to obtain a whole sheet of silica gel vibrating diaphragm; and blanking the whole sheet of silica gel vibrating diaphragm that has been removed of the two layers of the base material to fabricate a required silica gel vibrating diaphragm. As compared with conventional solutions, the technical solution of the present disclosure has the advantages of simple molding manner, low cost, various styles of the vibrating diaphragm, and small thickness of the vibrating diaphragm.