Method for controlling and reforming ultrahigh final boiling point of high-octane gasoline blending component

The invention relates to a method for controlling and reforming an ultrahigh final boiling point of a high-octane gasoline blending component. The method comprises the following steps: feeding C8 into the middle part of a xylene tower; after xylene fractions (at the top of the tower) as the heat sources of other heat-used devices are cooled, returning the xylene fractions to a reflux accumulator at the top of the xylene tower, pressurizing the xylene fractions, then returning part of the pressurized xylene fractions to the xylene tower to serve as reflux, and cooling the rest part of xylene fractions to serve as products; carrying out fluid-phase side-draw on the side high-octane gasoline blending component at the lower part of the retention section of the xylene tower so as to draw out C9 to C10 components, after carrying out waste heat recovery on the C9 to C10 components by utilizing a heat exchanger, cooling the C9 to C10 components and then sending the C9 to C10 components to a storage tank, wherein the drawing amount of the C9 to C10 components are subject to flow control; taking heavy components at the bottom of the xylene tower as the fuel oil of a heating furnace; and setting temperature measuring points at the upper and lower parts of the xylene tower and a side-draw plate, adjusting the product drawing amount at the top of the tower by a differential temperature controller, and then through the temperature variation of the side-draw plate, controlling the final boiling point of the high-octane gasoline blending component. The method has the advantages that the final boiling point of the side high-octane gasoline blending component is monitored by using a soft measurement method; and the obtained gasoline blending component yield is high, and the energy consumption is low.