The invention relates to a sectional type optical fiber preform sintering furnace device and an optical fiber preform rod sintering method adopting the sintering furnace device. The sintering furnacedevice comprises a furnace core pipe and a guiding rod capable of moving up and down, wherein the furnace core pipe mainly comprises an upper pipe body, a heating-section pipe body and a lower pipe body, the upper pipe body and the lower pipe body adopt quartz glass tubes, the heating-section pipe body adopts a high-temperature-resistant pipe body made of high-temperature-resistant materials, andthe upper pipe body and the lower pipe body are detachably and fixedly installed at the upper end surface and the lower end surface of the heating-section pipe body. The sintering method comprises thesteps that optical fiber preform rod loose media is fixedly installed at the lower end of the guiding rod, and is fed into the furnace core pipe through the guiding rod to be sintered. The sectionaltype furnace core pipe provided by the invention is long in service life, the furnace core pipe does not need to be replaced after cooling to room temperature, and can be heated again to be used, andthe heating-section pipe body of the furnace core pipe can be replaced independently, so that the reduction of production cost is facilitated, and the improvement of the quality of optical fiber products is facilitated.