Gas sealing device of optical fiber fusion shrinkage resistance furnace, and optical fiber fusion shrinkage resistance furnace

The invention relates to a gas sealing device of an optical fiber fusion shrinkage resistance furnace, and the optical fiber fusion shrinkage resistance furnace. A gas inlet end sealing assembly is used for being assembled on one end part of the resistance furnace, a gas inlet end sealing assembly is provided with a first annular gas channel, a second annular gas channel and a third annular gas channel which are sequentially arranged along the axial direction of the gas inlet end sealing assembly, the first annular gas channel faces the outer side of the resistance furnace to blow out a first protective gas along the surface of an optical fiber preform, the second annular gas channel faces the optical fiber preform to make a second protective gas approximately vertically blown to the optical fiber preform, and the third annular gas channel faces the inner side of the resistance furnace to make a third protective gas blown in along the surface of the optical fiber preform; and the gas outlet end sealing assemb