The utility model relates to the field of silica gel, and in particular relates to a heat-conducting insulating sheet composited by addition type cured heat-conducting silicon rubber and glass fibers. The heat-conducting insulating sheet comprises a heat-conducting organic silica gel layer, wherein glass fiber layers are arranged on the upper and lower sides of the heat-conducting organic silica gel layer; and adhesion surfaces fixedly attached to the glass fiber layers are arranged on the upper and lower sides of the heat-conducting organic silica gel layer respectively. The heat-conducting insulating sheet has the beneficial effects that the heat conducting coefficient of a heat-conducting silica gel sheet is 3W/m.k, the compression rate is 65 percent under the condition of 50Psi, the Shore hardness 00 is 5 degrees, and the breakdown voltage is 6kV. When a product is applied to an electronic product, the heat-conducting silica gel sheet can be compressed to enable the thickness to reach the required thickness, and cannot spring back, so that a plastic cover cannot be deformed.