Thermal protection shield for polycrystalline silicon reduction furnace, and preparation method thereof

The invention discloses a thermal protection shield for a polycrystalline silicon reduction furnace, and a preparation method thereof. The thermal protection shield comprises tubular bottom sections, tubular middle sections and tubular top sections which are assembled from bottom to top into a tubular thermal protection shield body coaxially arranged in the polycrystalline silicon reduction furnace, the tubular bottom section and the tubular middle section adjacent to the upper of the tubular bottom section, the tubular top section and the tubular middle section adjacent to the lower part of the tubular top section, and the vertical adjacent tubular middle sections are respectively connected by spigots, annular bosses are respectively arranged at the outer sides of the bottom of the tubular bottom sections, the tubular middle sections and the tubular top section; the preparation method comprises the following steps: determining the size of the tubular thermal protection shield body to be prepared, determining